Of Springbank's Port, Bourbon and Rum finishes, I hear that the Rum was the best of the bunch. So far, I haven't been able to find a bottle and see for myself...
For my money, the Springbank Bourbon is way too hot and is one of the few SMs that I'll add a splash of water too. Settles down nicely after that and opens up on the nose. However, I find that you have to be careful in how much water you add, just a little too much and the whisky drops off a very sharp cliff...
On the other hand, the Port version is quite nice by itself and does not overpower... That said, I don't know that either would be my choice as a daily drinker; they're more interesting as a change of pace...

