Can’t really tell anything on the specific models but when we started to use asterisk 2 years ago we purchased 20 grandstream GXP2000 phones. We had trouble with 14 of them. Randomly resetting, BLF lights acting strange, calls dropping etc.
We replaced all the grandstreams with Linksys SPA942 phones and never had any problems at all (at the moment 30 phones in use for about a year and not one with problems).
Couple of months ago we started testing videophones and we purchased a Grandstream GXV3175, a Tiptel VP 28 and a Yealink VP 2009.
The grandstream crashed randomly and software responded very slow… That was the last time we did anything with grandstream, we really hate those phones 
At the end, we are now working with 10 Tiptel VP 28 phones and are very satisfied, no problems so far. As for the yealink phone, it is exactly the same as the tiptel vp 28. Don’t know if these are the same companies but try googling that phone, you get the exact same phone but with different manufacturer labels