Sandybridge cpu upgrade advice

Hi guys
heres the deal... i have a limited budget of £90 and im looking at upgrading my pentium G620 ... now i know a core i5 would be the obvious choice,and a core i3 would also be ok.. however from what ive discovered there wouldnt be a massive increase in performance moving from the G620 to a core i3...
however i keep on looking at the "Intel Pentium G2120 "( http://www.novatech.co.uk/products/components/processor... ) which at £59 has a 500mhz increase on the clock speed (compared to my G620 ) and also has the newer "ivybridge" architecture
i understand there wont be a mindblowing improvement ... however there must be some improvement giving the 0.5ghz increase in clock speed ....
ive also stumbled across a core i3 2100 for just over £70 and im very tempted... it will finally bring me into the "core i" range of processors and will also give me hyper threading
however will i see a worthwhile improvement .... im not expecting miracles,but will my system feel quicker .... my current system specs are as follows
pentium G620
8gb ddr3 XMS3 corsair (1333mhz) ram ( 2 x 4gb )
gigabyte ga-h61ma-d2v mobo
ASUS GTX550ti (1gb )
128gb ocz octane ssd ( windows boot drive )
1 x 500gb sata HDD
500w ocz stealthstream psu
samsung writemaster dvdrw
ive checked the gigabyte website and my motherboard requires a bios F4 or better and since i flashed the mobo to F4 when i bought the G620 it should work without any problems ...
so shall i take the plunge and get the :
1)pentium G2120 or
2)core i3 2100
any advice will be much appreciated
cheers guys !