I attended HGS but subsequently swithed to KE. Honestly, once you settle in, there was no real difference, except for level of facilities, which again, did not hugely affect the daily experience. With hindsight, I don't understand basis for negative reviews, except HGS is competing with a really powerful "KES" brand.
Everyone is aware HGS is part of the proposal to join the KE multi academy trust and its name will change to I believe KE Handsworth boys so it will be part of the same brand soon if the proposal goes ahead.
I think if you DYOR some boys have gone to the very best Universities including Oxford in the last 3 years.
On the schools website 40% A or A* in GCSE and 96% pass rate A* to C in 2014 to 2015.