I bought a Fissler 8.5 pressure cooker on Woot in early November. I have yet to use it because mine is defective. There are two valves in the pressure cooker. I first noticed that the one under the handle was defective - it kept spewing steam - would not stop. The Fissler Customer Service person referred me to her boss for an answer, but getting that answer was delayed she was traveling, etc. etc. Eventually, she sent a replacement valve and when I installed it, the handle problem went away completely, only to reveal that the second valve under the small handle is also defective. Now a replacement for that is being sent.
If you buy one of these, be sure to compare how it is working to the video on youtube:
If you don't know how it is supposed to work, you may think that steam coming out is normal - like my old, old pressure cooker, and be using a defective product.
As far as size goes, there is this information on the Fissler site:
"1–2 persons >2.5 l
2–3 persons >3.5 l / 4.5 l
3–4 persons >6.0 l
4–5 persons >8.0 l
5+ persons >10.0 l"
All that said, if I can get this pressure cooker to work properly, and so far I have only boiled water to test it, I think it should be quite good. You can use the pressure cooker as a regular pot by moving a switch on the handle. With only water inside, it reaches the pressure point in only a few minutes. The 8.5 qt is big, but not too heavy itself - filled with food, may be a different story.
The customer service boss is very helpful, but very busy, so a lot of patience has been required. I am hoping for a January pot roast.
These Blue Points have been discontinued which has me a little worried about replacement parts such as o-rings that are supposed to be replaced every two years.