Are noise gates/suppressors worth it? And there are a few on the market, MXR, Boss etc.

They get rid of that annoying buzzing sound, and help get rid of unwanted feedback. They usually work best for applications that require more gain. ISP decimator is the best IMO.
My Gear:
Schecter C-1 Plus with EMG 81/85(18v mod)
PRS Tremonti SE
Randall V2
Genz Benz G-Flex 212
BBE 482i Sonic Maximizer
ISP Decimator Prorack G
well worth it!!!....one of the few pedals that will actualy put a smile on your face,....try the variety that have an independant loop,....
Ive heard the ISP is the best, most noise reduction with the least clipping of your tone.

I heard baddddddddddddd things about the Boss one.