I own both as well and like them. I use the SB for 3.7V and the Xh for 5V. Both work great and are well made. The SB requires virtually no maintenance and the Xh requires period cleaning of the switch.
A couple of differences...
The SB is larger and heavier but can accommodate a bigger battery, which will last longer. Also, the SB's button is on the atty end of the unit; the Xh is on the opposite end. I find the Xh a little awkward because of this, but you get used to it.