Modest_Man, you want to look at options, options, options..... Once you hit a certain quality level, all the toons are basically the same.
Go to Fishermans and other outdoor shops and look at what they have on display. Also, keep your eyes peeled when you see toons out in the "field" being used. You will then have a feel for frame constructions, tube length, tube covering options, etc...
Then decide how you will use it... lakes, streams, white water class I, II, III, etc... That will steer you toward what will be suitable, un-suitable or overkill.
My best advise is to look for options: Gear bags, Rod Holder, Anchor System, Rear Platform, Engine Mount, Weight Capacity, etc.... You would be surprised how many times I am usiing mine and I come across another fisherman who has a huge toon that is a really nice brand but has very limited gear bags, no way to mount an engine (electric of course), etc..
Mine is rated for class II rapids... more than enough for me and my needs, has a 400 lb capacity.. more than enough for me and my Minn Kota, has three gear bags per side - enough storage for all my gear, the fish I catch, lunch and about 18 beers with room for ice to keep them cool. It has a rear platform, engine mount and full anchor system that can be used on both sides of the boat. My biggest thing is storage - and most toons do not come with much storage unless you get into the real expensive ones... With mine, I can go out all day and never have to return for anything.
That is my advice - everybody has different priorities/needs but, I have never heard anybody say they have too much storage or too many options !!!