Powertec 6" Jointer
1. The 6" jointer is big enough for most projects, has small footprint, bench-top style, and is inexpensive. On the other hand, the 8" jointer can handle bigger projects, is a much bigger machine though, free-standing model, and is more expensive. So you should consider your own situation in deciding the model. The 6" model is much more popular now, but that doesn't mean you can not have 8" model.
2. Powertec brand is new, but the manufacturer is not. According to it's company portfolio, it has done OEM for many major brands for 30 years. That's why you may see the similarity when you compare pictures of Powertec product with some major brands. My impression is that their planers and jointers are good because they are major supplier of both.
Hope this will help!