I wanna throw a Noise Gate into my effects loop on my B-52. Should I get an MXR M135 Smart Gate or an ISP Decimator? What's the major difference between the two? Also, would I put this before or after my Sonic Maximizer in the effects loop? The sonic maximizer is the only thing I currently have in the loop.
ESP LTD EC-400 Archtop

Robert Keeley Ibanez TS-9 Tubescreamer-
ISP Decimator-
BBE 482i Sonic Maximizer-
B-52 AT-100-
Basson B412-4
The ISP is the best, I would guess you put it after the Sonice Maximizier.
As I see the ignorance of humanity engulfing reason and sanity like a wave of perpetual defeat and misery I ask myself, when the hell is everyone going to shut up and actually think?
Noise Gate goes after all the effects in your rig.
'11 Gibson LP Jr.
'07 Gretsch 5120
'69 Tele
'10 Godin 5th Ave. Kingpin
'03 Blueridge Dreadnought
'02 Custom Martin D-28
Premier Twin-8
Fender Hot Rod Dlx
Boss SD-1
Consider the Boss NS-2 also. The noise gate doesn't always go after all your other gear. Things like a volume pedal or reverb would go after it.
It's a fine line between clever and stupid.