I own an ICS M4 myself, just successfully downgraded her with an M90 spring so she is now shooting 350 FPS not the 380 she was previously. So I can vouch for how easy the gearbox is to work on. Now lets hope I did it right, playing on Sunday 
On PEQ, personally I hate fighting to get my mini bat in the foregrip, it does fit but I on the reverse hunt for a nice PEQ to put the bat in for simplicity. My mate has the ICS anniversary edition and its PEQ holds 2 mini batts. So he can carry main and spare, just plugs in one and tucks wires away from the other.
On PEQ, personally I hate fighting to get my mini bat in the foregrip, it does fit but I on the reverse hunt for a nice PEQ to put the bat in for simplicity. My mate has the ICS anniversary edition and its PEQ holds 2 mini batts. So he can carry main and spare, just plugs in one and tucks wires away from the other.
