They are prohibited where I live due to barrel length otherwise I would have one myself... But I have experience with Raging Bull .44 mag (which is what the 444UL is based on) and it's a great gun. If you do a search here you'll find a few thread on this gun.
Just happen to have a Gun Tests for Sept.2007 sitting here. The model 444UL was one of the revolvers tested.
So were the S&W 629, which flunked the test badly, received an F rating. And the other was the Ruger Redhawk KRH-444.
Ruger received an "A" for all around performance.
S&W 629s cylinder wouldn't cycle or lock up properly.
The Taurus was given a C grade.
Testing shooters liked the Taurus grips,sights,light properties,and as an all around gun.
Trigger pull was considered as inconsistent though. This was thought to be because of empty cases or the rounds caused resistance problems o rinterference with rotation. It was thought that simple refinement was all that was needed. Since this was written is very possible the trigger problem is somewhat overstated or that Taurus,who keeps their ear to the ground, knows of this and may have dealt with it. Members here have not reported any trigger problems that I know of. If wrong let me know.
Accuracy was in the 3.1-3.4 inch range at 25 meters with .44 magnum ammo. 1.8 inches with .44 Special Winchester Silvertips.
Gun Tests tests are valid in most of what they report, but some of their testers at times seem a bit novice or unsure how to shoot all the various models and do them justice.
So, there it is. Warts and all. At least form that source.