to answer the OP, Yes and no.
they are a very nice design, very robust, but there are a few niggles.
The main niggles are down to 2 things :-
1)the fact that they share a lot of features with the TM PSG-1, they have the same pre-cocking function, they use the same pistons/springs etc etc. if this is not desired, this can be sorted with a conversion to normal AEG standard (it involves replacing the piston, spring, and sector gear with the addition of a spacer between the piston and piston head)
2)And the "blow back" ... basically the mechanical blow back merely rattles the fake bolt, it can and has been known to break, very easy to disable it though.
3)the triggers are known to burn out, this may in-part be due to point 1
That said its a good gun, and has one of G&G's great hops (par with TM imho) ill admit i have had a few issues with mine, but i bought mine 2nd hand (and it was in a bad way), and have restored it.
FYI the army R85 is a clone of the G&G L85
as for the ICS, they too have a few niggles, best to have a look in the review section, AirsoftEd has done a great review there.