Re: Pilot acs...?
The pilot is a better marker than an aggressor in my eyes.
You will be choping less paint, plus the aggressor is Mechanical vs Electronic pilot. The pilot Semi-Auto up to 20 bps, 3-shot burst, 6-shot bursts, and full-auto. It also has a top-cocking ACS (Anti-Chop System) bolt, a removable feedneck and comes with a drop forward. It comes with a quick release pin so it's a snap to get to the internals where it's a simple over/under blowback paintball gun. All in all the pilot is a descent Entry-level marker.
Although I bet a could find 1 for cheaper than 100 bucks.