Time to add my two cents
never owning an ics myselfor a g&g I will stick with the facts that I
know first hand. First of al let's not compaire stock tm
parts to the ics or g&g parts as stock tm guns have low quality shit internals if you plan to add an m120 spring
without any other upgrades (before I get flames... I said internals. Externals are lovely).
I can tell you this. You could spend $600 on an ics sig 552 but you will be crying after words. The battery issue is a big factor unless you want to run a peq box. Also ics guns tend to have parts specifically for ica guns and
speaking from experience after market upgrades for them are a pain in the ass to modify the fit.
That being said until more info is released on the g&g sig 522 your only other option is a cyma 552 (don't buy the jg they are 99.9999% identical) as they are cheaper. Now I can tell you a place to buy one for $149.99 in canada, ordering online. That being said if you go full metal huang has a very nice front set he sells for $60 and cottoni sells hurricain metal bodys (yes I own one) for around $320. You now have the option of using tm
or MAG mags in the guns giving you access to low and mid caps. The cyma fires farily fast for a clone gun. You can fit a 10.8v 1500mah nimh battery in there from cheapbatterypacks packs.com (contact me for more info if you want the design specs).
The only major downside is before doing any internal upgrades to the gun you will need to replace the gearbox shell. It's not made to tm compatible specs with bushing sizes or cylinder head areas. Basically what I am getting at is a cyma could turn into a very nice
project gun but it will be more costly than the ics gun stand alone. Wait until we get so e reliabilty posts on the new g&g models if I would be in your shoes.