Hi-capa 5.1 is very reliable. You could even use it as your primary.
You may also want to consider the TM 4.3. It's a short by 2 rounds against the hi-capa, but it's shorter slide and built in rail are factors to consider.
I use both since you could also interchange their mags.
The 5.1 is not a replica of any other gun. The 4.3 follows the steps of a real steel 2011 though - used for competitions and by some tactical teams.
The 5.1 has tons of parts; so does the 4.3.
The 5.1 has bomar sights; the 4.3 has fixed.
You could draw faster with the 4.3 due to its shorter barrel.
They're pretty balanced against each other so ended up getting both!

More than 6 months already, with weekly games and both perform up to par.