Well the Complete extended foreplay is $600 so if you wanted to invest even MORE money into it making it even better you would still be in for less than a candela. Perhaps I should rephrase my original statement though also, Im really not sure if it would be better. I really have no clue to be honest. I have never heard the candela or the tempest. I know klaus's products are an outstanding value so automatically they are hard to beat. But I have been pretty impressed with my Foreplay II, Stock i will admit that it was just fine but after some of the mods ive done to it it has really improved dramatically. It sounds better than the preamp section in my old NAD integrated as well as an Audire Diffet 2 preamp. From what I have read on the bottlehead forums folks are claiming an astounding improvement in the extended foreplay III vs the II or even stock III. That makes me think wow this thing must be pretty good! So knowing how good the candela is supposed to be and how good the foreplay III is supposed to be I just cant help but think that they would be similar in sound quality.
Build quality wise of course the candela wins hands down. It looks alot better, is made better, and comes from someone we all trust. I wish i had the chance to compare all of them to draw any real meaningful conclusions, But I know that there are alot of folks who have built these foreplays and replaced much more expensive equipment. Plus, I really like being able to build something myself and design a chassis the way I want it to look which is exactly what I would do If i ever bought a FP III