Yep on personal appearance, nobody should get bunched up over whats given from one persons OWN opinion, take that with a grain of salt. What looks poor to one, may be great to another.
As for testing guidlines, and the obnoxious inconsistencies on how a product is review. Here is what I think:
A. No problem giving a subs max SPL point right below driver compression with the natural frequency response from X hz to Y hz, with an accomanying plot showing the differing order harmonic distortion along with group delay.
B. This same test should then be performed -3db down from compression point which should be right around half rms power. Again give specs like group delay, and the order harmonics. This same complete test should be performed once again at minimal power of around 1-2 watt rms depending on an 8/4 ohm load.
C. There should be also be a test performed to find the true sensitivity of a given sub. Sensitivity is rarely given. This alone would be a good measurement given to find out roughly if you sub solution your pondering can
keep up with the main system speakers. SUbs generally have much lower sensitivy values that typical speakers today. So knowing if a single sub(or possibly if multiple subs are needed) can keep up with the dynamic capabilities of your main speakers would be good knowledge to have.
For example one of systems has a 200x5 power amp running speakers with a sensitivity value of around 87-90db with 1 watt/8ohms. I run 3 15" subs in parallel (grouped together)to make sure I have enough dynamic range to not clip the subs even at high output bursts. It allows me to keep the gains much lower reducing any potential for harmonic distortion/clipping and gives my subs much better dynamic abilities to keep up with my main speakers. Now I know my speakers probably only use 1-2 watts rms during normal playback, but there are without question plenty of dynamic bursts that will easily hit 15-20db over normal RMS power output. Now if I was using just one single 15" driver, to equal my main speakers at 1-2 watts rms, it would probably have to be outputting 16-32 watts rms or even a bit higher even. So I run a few extra to drop the amplifier output so that each sub RMS power is closer in line with my main speakers. What I wish I knew was the true sensitivity of my sub so I didnt have to guesstimate how many I would need to keep the dynamic capabilities in line with my main speakers. So as budget has allowed, Ive added a couple more in the process. I will probably run a total of 4 when funds allow.