Mixcraft- wonderful for home studio mixers, weekend warriors and such so long as you don't want to get too complex.Like a pimped version of Garageband. It offers a lot for the asking price.It might do all you need it to do though.
Studio One- It has the capability to go deeper than Mixcraft and offers more features.
Cubase- If you used the deep midi functions in Sonar, this is probably your best choice.More of a learning curve. The other two can do similar, they aren't as complex in midi DEEPER editing functions. Really nothing can replace what Sonar does completely. As in any daw decision it's subjective depending on what you want to do and how you like to do it.