The PE20 is not a CV carb, so I would expect them to be easier to tune indeed.
Also, slide carbs are _said_ to have a quicker throttle response than CV carbs...
In my experience, the tiny difference in throttle response time (if any) can only be relevant for manual shifty bikes, where you have to open/close the throttle lots of times to get somewhere, not for our "just twist and go" automatics...
And, I also think that the advantages of a CV carb are worth the extra bit of effort for learning how to tune and maintain them. To be honest, I think that people who can't get a CV carb setup right would also struggle with a regular slide carb, unless they're just lucky... The simpler construction of a slide carb increases chances of getting it right accidentally, I think that's one of the reasons they're so popular...
Another thing to consider is the way the throttle cable is installed... It comes out of the top of the carb, and since it can only bend so tight and you need to allow for some headroom because of the rear shock compressing, you'd probably better forget about using the underseat storage for anything else than the throttle cable with these carbs...
Personally, I would look for a 20mm CV carb instead...
Just my thoughts...
