I've never been a huge fan of the bourbon finishes--think Macallan intro'd some of those as well. The goal seems to be to convert bourbonites into whiskyites. But, like Transnova, I had one of those bad experiences that leaves me unable to appreciate the finer points of bourbon. Or any other points of bourbon, for that matter.
On the other hand, I'm a big fan of aging whisky in old Madeira casks from Spain, the way Macallan does it. Seems to smooth things out very nicely--Springbank is aged in sherry casks as well. If I were to experiment with altering scotch, in fact, it would probably be to add a small dose of sherry to it... (I like lagavulin on occasion as something different, but the islays are too iodine-y for me. Hence adding liquid smoke doesn't do much for me, even if it was a perfect solution.)