I've flown the Seneca II and it is a nice aeroplane to fly. The beauty of the Seneca II+ is that it is turbocharged so good for FL250 if you want. Not sure about the Aztec. Overboosting is possible but it doesn't take long to get used to not firewalling the throttles all the time.
The one I flew had a vortex kit on it so lower Vmc, and de-ice so a pretty capable aeroplane.
I guess a lot of it depends on your budget and what sort of flying you will be doing.