Aug's can be decent if you invest a little time in them.
It's not worth going for the TM HC if you are going to tweak. There is nothing special about the HC other than the fact it is 90% there in terms of tweaks already done.
The bog standard AUG has an awful lot going for it.
It's cheap, mags are cheap, It's light, It's comfortable to shoot.
It is not an M4 platform and works differently. The biggest difference been that an AUG needs movement on the internals. If you start to shim things up to be tight that is when body pins start to fall out.
the aug's are nice although from what i've seen on the field they seem to have this strange knack for spontaneous dissassembly
You'll probably find the owner shimmed the barrel or incorrectly installed the hop unit. It stops the hop unit and barrel free moving, keeping spring tension on the body pin. Without the tension the pin will just fall out. And the gun will fall to bits. It's one of the most common problems I see with them, And it's 100% user caused because they read a guide for the m4 platform and assumed it works on all guns.
Personally ATM I would get an AUG commando variant. I've said this a fair bit in the past year. It's the best overall variant. Offering rail space, A more suitable inner barrel length, And better overall styling. It can also be had cheap if you go searching for JG/APS re-brands.
https://gunfire.com/en/products/sw-020t-carbine-replica-olive-drab-1152215958.html
Upgrade wise from a bottom end model like that you are looking at an overhaul.
Element silent piston and cylinder heads (you want the pom plastic ones). £15-20
Mosfet £10
Motor It'll depend on if you want to alter the gearing. For 7.4v 2200mAh block batteries on 18:1 gears about 35K is adequate for 25rps. £50
Downgrade spring M110 cut (it has a QC system on that model) £5
Decent bucking £10-15
Better inner barrel (320mm) £20
So £100-120 in upgrades off the bat. It'll still bring the gun in at under TM HC prices. But for the effort you will have a better overall shooter just a touch slower on the RPS.
The rest of the AUG is just learning the platform. There is one minor problem with BB's getting into the body, It can be reduced with some magwell shimming. Getting the BB's out is a very simple affair just split the gun, invert and shake.
My own AUGS hold there own on the field. I've never felt out ranged by another AEG, Or at a disadvantage. The gun is comfortable, Points well, Well balanced, and extremely easy to work on.
Aug triggers are less good. They have travel, and no real feel to them. You can modify the selector bar for a semi only position if needed with hand tools. And still retain the semi/auto position. The trigger is nothing like a PCP gun. It's functional, and works best when silicone oil/grease is used on the trigger plate over the pistol grip to give it some smoothness.
