Just got the datasheets, and it certainly appears that the PMT is not facing any serious competition. The APDs are about 500 times less sensitive (in a amps/watt basis), and I haven't looked at the noise floor yet, but I'll bet that you can't just hook a 500 gain amp on it. Losses through optical components to focus down would also probably zap you too.
Interesting that they claim one advantage over PMTs is that PMT's need a HV power supply. Well, heck, so do the APDs.. 1800V
Created on Tuesday, January 23, 2001 6:51 PM EDT by James Lux