I purchased mine from them. What can I say, it is an RO/DI unit. It is very high quality and they do use excellent material for the filtration, but I don't think there is anything wrong with Water General either. There are a lot of people that get away with tap water or even poor RO water so I think any of these will get the job done. If you are looking for the best, look elsewhere but if you are looking for something that works. The filter guys are a great place to start. Keep in mind they also have an excellent service reputation as well. I can take some pictures of my install if you like, but it doesn't look much different than the pics on there site.
I would add, the instructions from them were very thorough and easy to follow.