I am using the classic orientation.
A few suggestions:
1. Not everyone wants the output on the left side. How about a simple setting for left, center or right justification under General Options. Another option for resolving this that Shareaholic used was to allow manual placement (turn off automatic placement and provide a line of code to be manually inserted where desired).
2. The link back location is too large and prominent. I would be more inclined to link back if you placed it beneath and to the right in small type...AND because link juice is important, made it a nofollow link (or at the very least, make this an option with a checkbox). I'm willing to share a good plugin thru a link back, but not willing to give away link juice like that. I'd rather pay a couple bucks than give out a link that hasn't been no-followed.
3. Yes, please...add Google Plus and Pinterest to the primary button selection. At this time, both are considered essential social networks.
I have been using Shareaholic up til today, and I must say, yours is the best replacement option I've seen...but I will like it much better once you get these little issues taken care of. Thanks for your consideration!