Yes, they do work. While they are small, they are effective. The WSN IR system is much the worse for realism. The HL tanks shake and wiggle when hit/killed but there are no lights. The WSN sounds like a battleship alarm and is very odd. The DBU is very realistic and effective. The Tamiya TBU is the best so far. The Elmod and SLU are getting closer to the TBU with each version but not as close as the DBU is now. IMHO
The range of the HL IR is good but it's no TBU or DBU. The DBU has about 20% less range than the TBU. They are a cheap substitute, but you are very limited with how many tanks can play unless you buy some 5 the 10 HL radio crystals.

Bob, thecommander