The great thing about PML QT kits is they are easy to build if you follow the excellent instructions and the many FAQs they have on the website. Good epoxy is key, as is surface prep. I have switched over to Triple7 BP substitute, which leaves a lot less residue inside the tube and on the piston. Either way, you'll want to wipe out the inside of the airframe and the coupler portion of the piston to keep them clean and easy sliding. (Triple7 does require better containment than regular BP, but the piston design helps with that aspect of it. But as always, ground testing is always advised.
Of course the other big benefit of QT is how easy it is to finish. I've mentioned in several posts that my early success with PML QT rockets really got me hooked on HPR.
Tony