Camtasia = High Quality Screen Recorder
FRAPS = High Quality Game Recorder
Camstudio = Low Quality Screen Recorder.
I like how you commented that right after Alby
Well if you play around with the codec that Camstudio is going to encode in, it could end up as high of a quality as Camtasia. I find the uncompressed Camstudio codec that they have as well as DivX maxed out to highest settings makes it incrediably high quality...however the file size is about 1GB per second worth of whatever you recorded, lol.
Yeah it does get sharper because it is encoding the footage to whichever you use to capture with other than .avi, Fraps records in an uncompressed form of .avi but since the file is so large, after encoding it will make lose quality. However, like mentioned before, Camtasia is meant for screen capturing, not gaming. One of the main thing you'll notice is the frame rate, unless you have a incredible powerful computer (say 3+ GHz Processor). The only useless feature that in Camtasia is the built in video editor, since I already have Vegas to do that, I use the freeware Camstudio instead of Camtasia. Both works the same way, you just have less options to work with in Camstudio.
I don't recommend using Camtasia over Fraps if you are going to get footage from a game only because it consumes a lot of resource.
Oh to get HD on Fraps, the In-Game resolution has to be atleast 720p or 1080p or anything higher. Additionaly, you can modify it on Vegas, but you may see some blurs on the textbox.
While this is true, i have a middle-power PC but i can run engine and camtasia with little lag at the same time.