If we are talking 12s then the Kontronik 700-45 for the win my friend.
Less weight than the 5020, and more power.
Smooth power too, not that "flywheely" kind of power delivery the 5020 has.
I had a 5025 as well, but never used it.
I didn't like the "hit" the 5020 dished out initially before quickly running out of steam, and figured the 5025 would have an even more violent "hit" with it's increased mass.
The pyro 700-45 is the opposite, it comes on smooth/soft and then delivers tons of grunt. Makes life easier on the oneway and makes the tail behave better during hard collective application.
If we're talking 10s, then I'd go with the 5025 for sure.