I dont know where you heard that from but I dont think its true, I run 2011 Hs11's and find them a lot better than my 05 ones I used to use.
With a budget of £100 if it comes down to buying a new brake id advise a single 2011 HS11 (as it comes with a 4 finger lever blade, around £60 from tartybikes), a pair of TNN LGM pads (£30) and give your rim a grind if you havent already. Also if you havent already got one keep an eye out for a 2 or 4 bolt brake booster on here as that should help the brake as well!
And going off your original post maguras and v brakes are 2 completely different things, maguras are hydraulic rim brakes and v's are cable operated but can be just as powerful.