just_asking, if you permit, I'll offer my $0.02 worth.
If the SP will be carried for SD, even only occasionally, I'd go for the bobbed hammer. The first link that Jimbo357mag posted was a post I started about my SP. The hammer spur was catching on everything- pants waistbands, body armor and shirts when worn for a backup when I work at the PD, coats during the winter, you name it, the spur caught at least occasionally. Since removing the spur, I haven't had a single problem. Of course, my SP is carried all the time and is not just a range toy.
The issue brought up about shooting single action in a defensive scenario is also something to think about. Myself, I don't know of any cases where it's been an issue, but I'd bet that Massad Ayoob would if asked. Since he has, literally, YEARS of experience in the court battles that follow gun battles, I'd be inclined to take his word for it.
Axehandle also brought up a good point. While it does take some work and practice to become proficient in shooting revolvers DA, he is also right that, once you gain that proficiency, you'll likely never shoot SA again at "normal" distances. Since I started with DA revolvers, the vast majority of my revolver shooting is DA, even with my 4" GP100 that still has the spurred hammer. In fact, I've been considering bobbing my GP since I rarely, if ever, use the SA function, even at 25+ yards. In fact, I'd go so far as to say that I shoot better DA than I do SA with my revolvers.
What it all boils down to is that it is your decision, either based on your preferences or on what you can find to buy (DAO SPs seem hard to find). Either way, the SP is a GREAT gun and will serve you well for years to come.