I have the Gamo pcp hand pump and the Hill Mk. 5. Both have worked just fine, but the Hill seemed more efficient when pumping from 3K to 4K psi. In my experience, if your pcp only fills to ~3K, a hand pump is fine. However, if your pcp can go to 4K or more, you might want to consider an electric pump. I got the GX3 when I got tired of pumping more than I was shooting and it has significantly improved my airgunning experience. Good luck.