firstly sir i have written that demand is negotiable, which means i can negotiate...sir most of the branded amps are made in korea and china,or thailand etc. it doesnt mean the person can buy a korean amp like solid audio, instead of another xyz amp which is of a good brand but also korea. the person wont get the same quality of build and good components used in making the expensive ones....
indeed by specs wise the power ratings are quite same, but no one knows if solid audio gives the stated power or not, whereas the pg is cea rated and gives the stated power at all impedances....
it indeed is a plus point and so are others like the quality of components used inside is far more superior then local or chinese korean amps.
sir its not my 6th sense that told me pg is superior then solid audio, there are several several factors the specs of the amp says it all , and as far as going for branded amp concern , there was a discussion between u and usman (splfanatic) regarding soooolllllid aadeo f25000d and jbl gto mono amp...where usman was in favour of solid audio and u in favour of jbl, why jbl it has less power then solid audio but same price why buying jbl when u may get the overwhelmed sollllllliddd audio which has greater power, why to pay extra money just for the brand name...etc etc
the eficiency i was talking about was of the class thing like both amps are class d circuitary but the god knows how much % of power the solid audio puts after heatup, wheras the other amp has gone thorough tests by cea.....
yup this needs a good eletrical backup to run this amp at full potential, dual 4awg etc etc...
yup u have used alot of PG amps and i am sure , there must be reason also that u bought them , instead of getting a solid audio combo of 4ch and
2ch..... 
thankx for the compliment:)