eva8 with double tap is better than the mastiff imo, but ya - I called the mastiff being the noob-friendly PK as soon as I picked it up. More forgiving, wider spread, and it's easy to smack someone for an easy 65damage from 10m which makes it a force to be reckoned with.
I think the mastiff is actually really well balanced for a gun in that you can still out DPS it with many other guns - but it provides sustained DPS through a firefight and perhaps the best thing about it, is you can reload it partially, fire, and not lose your reload.
The PK will be missed, but I think it's good to shake up the meta once in a while. Having every single game come down to either a PK or r99 in the close-range slot gets a bit stale. Of course now, it's r99/mastiff (and a few renegade re45 users) but at least it's a change.