Hmmm, well ive only ever used one type of leathers so maybe my opinion is biased, but at least ive got some hard facts to support it.
I use the MotoGP Kangaroo Compression suits, EXTREMELY light and strong leather, ive personally crash tested these suits in over 6 race track crashes, many in excess of 160 KPH. Ive never had a bruise, scratch, or broken bone from any of my crashes so maybe im lucky, or this suit is just that good. The suit holds up VERY well against the road, I have yet to tear one of these suits or even split a seam.
The MotoGP Compression suit looks amazing for the price and the quality is easily comparable to Alpinestars or Dainese.
I am not to sure how hard to is to get one of these in Europe though.
Look here for more details:
http://www.motogpapparel.com/mgpweb.nsf/Products/C80069EFD9D62508862570B5006CA5C7?opendocument