I ordered 2 C100S54 Westinghouse Ceramalux lamps from the 1980s on eBay.  I was wondering if these were as good as their Mercury Vapor counterparts. (I.E. Do they last forever and a year before cycling?)  
I love how they look like the 100w clear Westy mercs.  But the ceramic arc tube looks huge compared to modern day chinese crap.  
They're good lamps, but not nothing like a Lifeguard.