The most ubiqutous YY string until recently, and still the staple here in UK. Average in pretty much everything except:
+ HUGE boom on heavy hits; durability is better than most
- Loses tension faster than everything else in the YY line-up, the effects being more noticeable the higher you go (I would add 10% to what you actually want); surface has quite a greasy feel, causing slices and spinners to slide rather than grip.
IMO, 65-Ti is an ideal "tournament" string - it's brilliant when fresh and plays wonderfully if you don't carry it for more than an hour or so.