if you wanna buy a good android phone
this is the best phone
for the spec and price
unless u wanna buy phone like S2

2.3 is not available for now
but most probably will be released in very soon
it's a bit easy to get hot at the back side but so far okay

lag is depend on how you use
S2 and ip4 can lag and spike like hell too
however,
x5 has 800mhz speed and can oc to 1.2-1.5 with stable
and ram is quite sufficient

definitely,
we all will suggest you to get this phone
if u wan an android phone, budget not more than 1k and dont mind the new brand