I just bought one the other day; mine is the new 8-shot .22LR model (like the bottom revolver in weblance's picture), not the older 6 shot version.
The SA trigger is very nice and breaks at about 4lbs after I put a dab of light grease on the sear. The DA trigger is another story. It is up around 16lbs based on my attempts to measure it with a luggage scale. My trigger scale won't go anywhere near that high. It's stiff enough that my wife (who admittedly has some health-related, hand-strength issues) can't pull it all the way through. The hammer is also pretty stiff to cock--she could manage it but the effort was enough that she was not interested in shooting it at all.
That's fine with me because I didn't buy it for her. I really like the little gun and this will make it very unlikely that she'll try to appropriate it.
I probably won't mess with the springs for a couple of reasons. For one thing, the SA pull is quite good at 4lbs so I don't see the point of spending money or time in that area.
The DA pull is, as mentioned pretty tough, but the trigger return spring, as nearly as I can measure it, is contributing 4lbs or less to the DA trigger pull. That means that even with no trigger return spring at all, the DA trigger pull would still be around 12lbs. I might consider trying a lighter hammer spring at some point in the future but I kind of like the idea of using this gun as a trigger technique trainer.
So if/until I decide that I can't manage the DA pull adequately, I'm going to leave it stock. I did take the hammer linkage apart and did some judicious smoothing/polishing. It didn't reduce the DA pull weight (as far as I could measure), but it did make it a lot smoother and that definitely helped it feel lighter.
I also replaced the factory grips with a Hogue monogrip. I found the original grips were too small for my hands. I hated to swap them out because I really like how they looked. I wish that Ruger would offer a slightly larger grip for the gun that would keep the factory look and allow the use of the factory wood inserts.
I'm going to have to shoot the gun for awhile before I can make a determination of whether or not I like the fiber-optic front sight. It seems ok so far but I haven't gotten it out in sunlight yet to see how really bright ambient light affects it. I did some experiments with using a flashlight to selectively illuminate the fiber optic to get some idea of how it's going to do in sunlight and the results were not particularly encouraging.
For whatever reason, Ruger decided NOT to use the excellent front sight system employed on the GP100 and the Super Redhawk for the SP101 front sight so none of those front sights will fit this gun. In addition, the older model SP101 sights won't fit either.
At this point I'm not seeing any other front sight options offered for the SP101 on Ruger's website (or anywhere else, for that matter). I guess I can always go low-tech and simply paint the fiber portion of the sight if it becomes an issue.
Overall, it's a nice little package. I'm sure I'll have more to say after I send a significant number of rounds downrange.