Duel Band what does it do and worth it?

Question

I am looking around to get an Airport Extreme.
I am looking at getting one because i read that it solves the WPA security dropout problem with the Macbooks, is this correct? So i can have WPA rather than WEP without any problems?
There seems to be a few around.
Airport Extreme
Airport Extreme Duel Band
Airport Extreme Time Capsule
Airport Extreme Time Capsule Duel Band
The Duel band on average can add upto £60 ($99) onto the price.
So is it worth it, what does it do really i am wondering?
Currently i have a cable modem (not ASDL) and have 2 macs running off it wirelessly, 1 ethernet connected and 1 pc laptop.
Also will the duel band really add anything, will it make my wireless as quick as being connected by ethernet for example?
Many thanks

Answer 1

Here are my thoughts:
*1) "WPA dropout"*
I have not heard of this but did a quick brush up on it. I don't know about this personally because I always use WPA2. I have an array of Apple wireless devices on my network and have not had any problems with dropout.
It may be an easy solution to switch your wireless network to WPA2 (or WPA2 Personal in AirPort Utility) and then reconnect your wireless devices using WPA2. This may solve your 'dropout' issue.
As far as "wireless security" goes, the order of security increases as you go from WEP to WPA to WPA2. Personally, I use WPA2 for all my wireless devices along with a long password and you should too unless you have a device (or devices) that can't use it. Unless any of the computers you listed are pretty old, they should all support WPA2.
*2) "Dual Band"*
The answer to this question relies on your answer to these two questions:
1) Do any of your devices work on "Wireless N" or 802.11n wireless networking?
2) Do you have any devices that only work on 'wireless g' or 802.11g?
If your answer is 'no' to the first question, then there is no reason for you to spend the extra money to get a dual band router. If all your devices only work on 'wireless g', then save the money and keep the single band router you have now as there would be no benefit to you if you purchased a dual band router when you could only use one band.
If, however, you answered 'yes' to the first question and 'no' to the second, then you have what some call a 'mixed network'. This means you have wireless devices that work on both frequencies (wireless g & wireless n). In that case, you would benefit from a 'dual band' wireless router like the Apple products you mention. Whether the extra cost is worth it to you is a question only you can answer.
Here's the difference:
The networking world is ruled by negotiating a connection. When any connection is negotiated, the two sides tell the other what their fastest speed is. They then agree to use their highest common speed.
If you have a single band router, it can only create one network. So any device trying to connect at a higher speed (like ‘wireless n’) will have to switch down to the highest speed of the wireless network before it can connect.
Having a dual band router is great because each frequency (wireless g & wireless n) have their very own networks. A dual band router can create two separate networks. One network for ‘g’ devices and one for ‘n’ devices. This allows all devices involved to connect at their best possible speed.
+Real world example:+
I have two AirPort Express' and an iPod touch. The Express' can work on either 'wireless g' or 'wireless n' but my iPod can only work on 'wireless g'
I had the previous generation AirPort Extreme base station which is a single band router so I had a 'wireless g' network running. I had it streaming music to the Express' and used my iPod to control iTunes all over the same 'wireless g' network. This bogged things down as streaming takes up a lot of bandwidth. This made using my iPod to control iTunes sluggish. The commands from the iPod had to wade through all the streaming traffic and that slowed things down.
With the new Dual Band AirPort Extreme, I now have two separate networks running, a 'g' and an 'n' network. This allows me to move the streaming traffic to the 'n' network so it will work better and frees up the 'g' network for iTunes control via the iPod and other devices.
Assuming any of your devices can use 'wireless n', you would benefit from a speed boost using the wireless network and accessing the internet as wireless n is faster than wireless g.
*3) Wireless vs Ethernet*
Ethernet is faster. I don't know of any real world situation where a wireless connection is faster than Ethernet. If you want more technical numbers on this you can read the section titled 'Wireless vs Ethernet (qualified)' at the end of this reply.
*4) Extreme vs Time Machine*
Only get the Time Machine's if you want to use the Time Machine feature of Mac OS X 10.5.x (Leopard). Your PC won't be able to use the drive for anything and any Mac's without 10.5.x installed won't be able to use it either. This choice alone can save you $100.00 or more.
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Wireless vs Ethernet (qualified)
The most common implementation of Ethernet in computers today is the 10/100/1000Base-T set of standards. the 10, 100 and 1000 actually refer to the speed achieved with each. 10 is actually 10Mps, 100 is 100Mps and 1000 is 1000Mps (also known as Gigabit Ethernet). Most computers created in this millennium support the 100 or 1000 speeds which means that those computers can run at either 100Mps or 1000Mps when connected with an appropriate Ethernet cable.
By the numbers, 'wireless g' and 'wireless n' are both faster than Ethernet 10 (10Mps) but as most computers can run at the faster speeds, Ethernet is always faster.
Let's compare theoretical maximum speeds (as no network speed given as a numbers is the exact speed you'll get when actually using it):
802.11g (wireless g) = 54Mps
802.11n (wireless n) = 70Mps
100Base-T Ethernet = 100Mps
1000Base-T Ethernet = 1000Mps
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Sorry this was so long. This is something that I've dealt with recently and wanted to pass onto others. Good luck!