Starter AEG Choices

[Caj109]

Hello Lads,

I'm new to airsoft only done it once few years back but plan on doing more and getting my defence when I can due to covid.

I'm still tied on what AEG to get. 

I was going to get a Specna Arms Edge SA-E08 but hearing about the gearbox issues I'm not sure if i do?

https://www.patrolbase.co.uk/specna-arms-rock-river-arms-sa-e08-edge-carbine

I've found some Cyma m4's but haven't a clue if they are any good or not hoping some of you lads have experience with this 

CYMA CM.623 M4 M-LOK

https://www.patrolbase.co.uk/cyma-cm-623-m4-m-lok-airsoft-rifle?pv=11537

Or 

CYMA CM.621 M4 KeyMod

https://www.patrolbase.co.uk/cyma-cm-621-m4-keymod-airsoft-rifle?pv=11521

I'm open to other brands that you lot have experience with and can vouch for.

I don't mind putting up a bit more for something more robust.

Thanks!

Craig.