Genuine Cortland is the best right off the spool, but certainly there is a great deal to say about how a wrap is finished.  This is true of both linen and leather.
The McDermott E-K1 that I refinished the wrap on took a bit of work and some different products, but the end result is really great.  It ends up being a cross between a great linen and fine leather feel.  I dig it.  Looks cool and feels great.  It was already trashed, so I wasn't worried about screwing it up.
The wrap on this McDermott I just got is perfect and really well finished.  So I am proposing to potentially screw up a really nicely done wrap.  LOL!
It's not a Bushka, so am I really worried about screwing it up? No, not really. 
Heck, if I screw it up I might even try my black hemp wrap on it before considering sending it to have a real cue maker do it "right". 
I don't have a lathe, but I am patient and can "wind string".  LOL!