I wasn't really referring to using VSTi's, I know all too well how frustrating all that stuff can get. But to make a sequence for a simple MIDI module, you don't have any of those issues, a mere MIDI interface is all you need. As for having to punch in a whole phrase to fix one note, I'm afraid that seems like a lot of work for a simple problem...
Perhaps the problem was WHICH MIDI sequencer program you used in the past? Personally, I haven't YET found anything as powerful, yet intuitive as Cubase. Forget all the audio and VSTi stuff. That is the cause of most instability anyway. Just use it for MIDI, and you are good to go. But when it comes time to quickly rearrange sections of a song (to try out different structures), when it comes time to say 'I'd like all the backbeats of the drum part under 64 velocity to be a bit louder' , when it comes time to say 'I'd like to quantize ONLY the backbeats and leave the ghosting untouched on the snare' or a myriad of detail editing that is a total PITA with a hardware sequencer, the computer sequencer rules, IMO...
I simply find the visuality of the thing (being able to SEE what you are doing) a major timesaver. Perhaps you could find a friend using Cubase, and see if it makes your old sequencer look clunky... But, trust me, forget about using VSTi's and audio, and you will have a pretty stable DAW...
I used to use built-ins for years, but the minute I got my first Atari and the early Cubase, I have never looked back. I can work ten times as fast as a built in, and to a higher level. I know your experience has been different, but maybe you just had the wrong software?