From My experiences,may vary for some people. I've handled both guns,I'm a bit biased to the G5 since I adore that thing after using it in a MILSIM but I'll try be open. I'm a bit of a whore for internals parts and long term reliability so factor that in as well.
WE SCAR L
Pros:
Nice and tough externals,next to no pot metal,CNC duralumin upper and very tough plastics used.
Sweet kick.
Nice sound
Based on a real gun
stock hop up performance is good.
Lots of aftermarket parts.
Overall a good upgrade platform due to it's friendliness to parts.
Cons:
Internals are fragile, made of pot metal cheese. Will defiantly need RA tech CNC steel replacements for long term use.
Cooldown resistance not great
Gas efficiency is mediocre.
Upgrade parts may be needed out of the box.
GHK G5
Pros:
Amazing kick,feels almost like a 9mm carbine. Heavy bolt and lightweight plastic body are a factor in this.
Fantastic gas efficiency
Equally as good cooldown resistance
Really good internals,very little reports on serious breakdowns,alloy but good quality and strong. Not cheap Zamak.
Good performances.
No upgrading needed out of the box.
Strong externals
Cons:
Full plastic externals(May be a con for some people,but not for me)
VERY loud. Not necessarily a con,but any stealth approach will be ruined by this little wasp.
Charging handle does not like HK slaps.
Does not like hop up rubber upgrades. Many reports of cycling issues and overhop problems with aftermarket rubbers.
Picky with how long you fill the mag. Over 6 seconds of filling you will have ROF inconsistency.
Not based on a real gun(Loosely based on a CZ skorpion evo,but with a 5.56 mag. GHK probably did this for gas storage reasons and copying the GHK PDW internals)
