I would suggest not to get that Mopic WE Hicapa those models seem to have a worse make
IF you watch Crunhmeister's video that model of the WE Hicapa the plain slide is the better one to get as you have a higher chance of having a gun that can work out of the box.
Also CO2 mags are great and will make the gun work fine but it will evenutally bash up the outer barrel and hop up unit which will cause it too soon jam up since the hop up unit was so mashed it will be loose
If you are going to go for WE I would highly suggest the WE MEU but if you really really want the WE Hicapa go for the plain gun metal slide and not the fancier ones cause the fancier ones seem to break easier than the plain one
- Pistolero Steve