Help with upgrading

[Drmalan]

I have 2 G&P m4's with stock gearboxes
I would like to upgrade to the fastest trigger response possible.
Looking for advice regarding who I can trust to do the job right.
Nothing against the techs at Vanguard but they don't seem to have the knowledge to do more than just basic repairs and in the last time I had them work on one of my guns they swapped out parts and couldn't seem to find the originals which I had wanted to keep as backup. So do I just try gearbox or is there some one independent that can do high quality upgrades here on the forum.
Was thinking about just giving up on AEG and buying a few polarstar engines but have heard mixed reviews and not terrible happy carrying around an air rig. If polarstar is the only way to get near instant trigger response than I'll just have to go that route but I'm hoping some gearbox wizard out there can do it with an AEG.
Thanks

[hdrox88]

Everyone seems to love Gearbox in Tempe. I've never had them work on my guns, I work on my own. Not to mention I live in Surprise. Depending where you are located, I might be able to help. I know there are a few others on here that know there way around a gearbox as well.

[Legion7]

Hahahaha Me and my brother had bad experiences with vanguard. They were horrible to deal with, kept no records of anything besides using their red tags, its a mess unorganized mess, and i could literally go on and on about how they tried to lie to us and stuff. But in the end they never fixed anything, lost my mag, misplaced some of my external pieces, and took gave me some pieces that were torn apart. 

Besides the point what were you going to upgrade in those? PM me i could probably even do it for you faster and better.

[ThatGuy]

Higher voltage battery will increase trigger response.
Try a 9.6 or a lipo

[Legion7]

Oh yeah, trigger response. I know there is some wiring stuff you can buy to help with that too. You can also short stroke it for higher ROF and swiss cheese the piston and properly shim it too.