As many of you know ... I sell a USB to Ethernet Adapter ... so this advice may not seem impartial. I'll try not to make this into a blog-o-mercial for my own benefit.
The biggest reason I would suggest using a wired connection vs a wireless one is:
Recently, one of my good friends, who had WEP encryption on his wireless router, noticed a big difference in bandwidth.
The lights on his cable modem and wireless router were going crazy - but his computers were turned off.
Because he had a high end wireless router from Linksys he could monitor the traffic incoming and outgoing.
He noticed that porn sites were being accessed, that LimeWire downloads were being made, and that banking sites he didn't visit were being accessed.
How could this be? He is a 25 year networking veteran. He configured the router with encryption and a good password. He also had the SSID (name of the router) hidden. In most scenarios this is enough to get rid of your average "piggybacker".
So, he and I went around the immediate area of his residence to see who might be "piggybacking" on his network.
* Some say the term "piggybacking" is parsing words with "thief"
We found that two of the neighbors had NO CABLE, NO SATELLITE, NO DSL, NO PHONE LINE going to their residences, but they did have WiFi signals emitting from their houses and a little spying showed us that they had pretty normal cell phones (so no tethering). With a little investigation - I also found out that those neighbors also had no 3G modems in their residences. By further research ... we found that traffic only crossed his wireless router when two specific neighbors were at home.
So, do we confront the neighbors? What would we do if we were the average joe and not know who was "piggybacking"? Simple, just move to wired connection and the problem is solved. No one can steal a wired connection ... unless they break into your residence.
He was asked a few days later by this neighbor if his cable modem was having trouble. That's odd - if my neighbor had a cable a modem - I would think nothing of the question and answer the question. But this question was coming from a neighbor that didn't even have cable,DSL, or 3G modem access going to their residence.
So, if your ethernet port is blown on your motherboard and you are considering just going wireless to solve the problem ... consider the scenario above.
Why would I use a wired connection in conjunction with a USB to Ethernet Adapter ... even if my ethernet port is fine?
I personally use this adapter on my black MacBook so I don't have to plug in my ethernet cable ... I just use a USB hub w/ two of these adapters so one can be hooked to the internet and one cable can be hooked to a network printer. I don't have to worry about IP addresses or the constant plugging & unplugging ruining my laptop's broadband connection port. The USB also stands an intermediary for surges from the network as well.
I also don't have to have a router - I can just use my USB hub as an ethernet router. I can use up to 16 USB to Ethernet adapters.
Even if you are using the fastest wireless standard ... wired ethernet will always be faster.
Wireless interference is a big part of the speed issues ... cellphones, poor electrical wiring, bluetooth, microwaves, wireless audio, even satellite TV remotes can interfere with the signal strength and bandwidth of wireless ... but to be fair 802.11n has remedied this to a large degree. Still ... most wireless networks are 802.11b or 802.11g.
Also ... your distance from the router and any obstructions (walls, etc etc) can affect bandwidth. Why sacrifice speed if you don't have to?
If you are using a laptop ... use wireless on the road or at coffee shops.
Wireless access comes at a cost ... power.
By using an ethernet / wired connection you can save 15% or more on battery life if you have a laptop. Just make sure that if you are going to use a wired connection that your cable is long enough. Never plug into your laptop with a short ethernet cable - you could do damage to your port.
This is another advantage of my adapter - it will pull out easily if "yanked" as most RJ45 cables lock into place in their ports.
Here is the text of my eBay auctions ... with the information above and the information below ... see if this might be a good solution for you:
EXCLUSIVE USB To Ethernet Adapter for All Apple Computers w/ PowerPC or Intel & OS 9.2.2 & Higher (including all versions of OS X)
Save a costly motherboard repair for your Apple: All In One iMac, eMac, Mac Mini, iBook, PowerMac, G4 Cube, Powerbook (w/ USB ports), MacBook, MacBook Air, MacBook Pro, Mac Pro, or G3 G4 G5 Tower or Twentieth Anniversary Mac (requires installation of PCI USB Card * not included)
I personally use this adapter on my MacBook so I don't have to plug in my ethernet cable ... I just use a USB hub w/ two of these adapters so one can be hooked to the internet and one cable can be hooked to a network printer. I don't have to worry about IP addresses or the constant plugging & unplugging ruining my laptop's broadband connection port. The USB also stands an intermediary for surges from the network as well.
This adapter works with ALL Apple operating systems (Apple's adapter only works with 10.5.2 & higher & is meant exclusively for use w/ the MacBook Air)
This can be used to replace your surged ethernet/broadband port on your Apple computer that you use for network, cable modem, DSL modem, satellite modem, internet access. Your ethernet port does not have to be bad to use this adapter. Get this in case of an emergency!
USB 2.0 & USB 1.1 standards compatible. One end is a standard RJ45 Ethernet/Network port. The other end is a standard flat end USB connection. You will plug your ethernet cable into this adapter JUST AS YOU WOULD your built in port.
Comes complete with drivers, manual, and instructions that I have worked hard over several years of sales to make as complete & comprehensive as possible.
This adapter works on Apple Operating Systems 9.2.2, 10.1, 10.2 (Jaguar) Mac OS 10.3 (Panther) or Mac OS 10.4 (Tiger) Mac OS 10.5 (Leopard) & all versions of Windows that support USB. Apple's adapter doesn't work in OS 9 or anything lower than 10.5.
This is NOT Apple's adapter - it's better. Apple's adapter is software based and may have some compatibility problems even with the MacBook Air. Apple's adapter is designed exclusively for the MacBook Air.
Best compatibility with Jaguar (10.2.8), Panther (10.3.9), Tiger (10.4.11), Leopard (10.5.6), & Windows 2000, Windows Millenium, & Windows XP Windows VISTA.
There is no need to open up the computer to install this. It is not complicated and even the most novice person can do it. I'm happy to provide phone & email support to you to make this work.