Dont you like the trackpad on your MBP?
I've haven't used the touchpad on laptops for ages, but the MBP trackpad is a very superior beast to most other laptops, so I might give it some time to get accustomed to the trackpad and then decide if I need something else.
When I unpacked the machine and realised how different the trackpad was, it did cross my mind that I may have been to quick to buy the MM.
Another problem I have is that my watch scrapes on the body of the MBP while typing - been taking the watch off, but wondered if others have an issue with this.