I use the Monster 1000 and love it. It seems to be a really well built product.
Do I think it makes my picture clearer or my sound crisper? No, I bought it because I wanted a very sturdy and nice looking surge protector.
Do I trust it? Yes, I leave it plugged in during thunderstorms all the time.
The one thing that bothers me about it, is that the 4 outlets on the video bank are only controlled by the 12v remote in and not by the main switch. (i.e. turning off the main switch will only turn off the audio outlets)
Other than that, It looks good and does it's job.
Is the 3500 better? Maybe? That's a cheap price for it, If I needed one I would get the 3500 just because of how much off it is, but I wouldn't expect any improvment except for maybe a few more outlets.
So basically, the choice is up to you. But buy whichever you would want as nice power strip and surge protector but don't expect it to perform miracles.