Some years ago I got four of them to place around the house because they were only $7 each at the time. The Kroll switch seemed like an improvement over the MiniM^g. At that price they are OK and if you put some Scotch Satin tape over the lens, the beam will be improved.
The lamps blacken rather quickly and I'm not aware of better ones for the Jr. Buy several packs of lamps when they go on sale. Brightness is similar to a MM with a HO lamp. The SL Jr. lamps draw about 400mA.