A lot of people sing the praises of MSE, and I use it on a netbook. For some reason I don't think it good enough for a PC if you use banking or similar sites. Not enough setting available for me. Anyway good hunting. (I dislike the overbloated, nagging Comodo.)
Comodo will be fine, but as you`ve noticed, it updates and nags at you more than some people can tolerate.
It`s mostly AV updates you`ll be getting now and that`s not a bad thing. (It used to be quite a lot of Vista compatibility stuff.)
Most of the nagging is from Defence+ which is a kind of internal check that nothing is running that shouldn`t be, or any changes in program behaviour that it hasn`t seen before ... it really doesn`t like changes to its protected registry keys.
Consequently, installing a new program can send it into a bit of a tizzy.
If you prefer Avast (or another AV), it`s best to install Comodo without the AV component to avoid possible conflicts.