Consider:
Other ready made QB PCP conversions were running +$250, so $199 doesn't seem out of line.
(The PCP do-it-yourself conversion kits cost $125...plus the cost of a new rifle....call that $200-$220 and you did the work yourself.)
IF you are use to working/tuning/modding a QB's, owning a PCP version makes sense. If you are use to getting the co2 versions to shoot great and run smooth, should be able to do the same for the PCP version.
Larger, higher pressure tube than a Disco.
QB trigger is a lot easier to get in line. Can get the Disco in line by drilling. taping, adding screws....the QB comes that way.
Have nothing against the Disco, have owned two, liked them both. Did order the PCP QB on 9/18... do expect it will be delayed in shipping (isn't everything?), but will give it a work out when (if) it arrives.
Will eventually try a .25 top end (from a .25 QB)... and might try a .20 top end (from a different QB).