I've got one of the last GST135's made before they changed the model over, and I've never been able to get a decent cut with it. I thought I'd try the festool blades as they are indeed thicker, slight problem is they won't fit in the guide groove on the thrust bearing on the GST135!! I ran one anyway just to see what happened and it didn't do the blade any favours, but they are definitely a lot better, but you can't really use them with the Bosch jigsaw :-(
I tried a carvex out a couple of yrs ago at the D&M tools show and was surprised how square it cut, but I think my next buy will be the mafell P1CC, that seems to be the holy grail of jigsaws.....Santa are you listening?