A good site for you to visit, is www.videoguys.com. They cover everything from prosumer to professional products. If you do some searching at www.videohelp.com, there are numerous comparisons on the different encoders. There seem to be pros and cons to almost all of them, and the difference between what some consider to be the very best, and the versions of encoders that come with adobe premiere, and vegas, and not that great. Unless you are doing commerical production work, you don't really need procoder. Vegas 7 in itself can encode, but the actual encoding software, and the authoring software are in DVD Architect. There are many folks out there doing high level professional video, using adobe premiere, and vegas 7.
Right now, the really good softwares for the home user who wants to tinker and have some artistic control, are Ulead Studio 10, Adobe Premiere Elements, Vegas Movie Studio, (and some like Pinnacle), then it goes up to the true professional softwares like Adobe Premiere, Vegas 5,6,7, Ulead DVD Workshop, Ulead Studio Quartet, Avid Xpress, and Canopus Edius. One must be very careful with the professional level softwares, as they are very hardware/software dependant (meaning, that if you don't have everything set up on your system exactly right, and everything installed in the correct sequence, and have the correct capture card/device), you will be in buggy heaven, and may not even be able to get them to work at all on your system.
If you have a true desire to go crazy with video editing, authoring, etc., I would highly suggest you try to find a good deal on Vegas 6 with DVD Architect. With the newer version out, you can find some pretty good deals. If you know someone in school, or who works for a school, you can buy the Educational version, which has everything the regular version has, at about 1/2 the price.
I've used quite a few of the products, and spent hours viewing tutorials on many of them. I was very impressed (just from hours of tutorials), with Avid/Pinnacle Liquid Edition software. Very friendly interface, and an extremely powerful software. Some people find it buggy, and others love it. I personally use Vegas 5, and find it will do anything and everything I need. I have a small home business where I converth VHS to DVD, and from camcorder to DVD with custom editing and authoring. It took awhile to learn the vegas software, but it was well worth it. I also had Adobe Premiere 6.5, which is a pretty good software as well. The versions I have won't handle HDTV, but that has not been an issue as of yet, and unless I start getting a lot of customers requesting it, I won't worry about it. If customers do start requesting it, I may just get Ulead Studio 10 Plus, just for bringing in video edited in Vegas, then encode with Studio 10, then use DVD Architect to author and burn.
Hope this helps...