You are right, I was thinking of MiG-21 and MiG-29 primarily, those are/were really bad in terms of pitch oscillations, haven't flown the 29 lately though, there might have been FM improvements in recent updates. The MiG-15 feels a little better in this area, it has other quirks though.
I'm not saying the MiG-19 FM is perfect, but I like the 'stiffness' of the control input vs. reaction precision. It feels a lot more like an 8 tons fast jet that pretty much goes where you point it.
My impressions stem from F-4F and Tornado full-flight sim time and the usual single engine piston aircraft.