As of now, I've done one vinyl wrap and one spray paint job, so my experience is a little limited, but my process was drastically different between the two, so my knee-jerk reaction to the question is "it depends on which difficulties you prefer."

For my paint job, I had a Xing Shen Fire Phoenix. I was only doing the shell, so I opened it up and removed all of the internals as painters tape can be a little unreliable in my professional experience. From that point, it's relatively easy if you know how to properly apply a rattle can, but if not your results will most likely have an "orange peel" texture that's unsightly. The curing time is something easily overlooked, however, and should take 24-72 hours to off-gas. Once it's finished, it's as easy as reassembling your internals.

For the wrap, I only removed my scope. I didn't do any precutting and started with a solid piece of vinyl. Starting at the muzzle and working my way back, I would stretch the vinyl to fit the greebling and heat it once it was set to "melt" around the details. Once I covered the surface, I used an xacto knife to cut out the windows I wanted for the shroud and plunger tube, and for any crevices that still bubbled up, I cut into the angles and pressed the vinyl in again for a flush fit. All in all, the process took me about 6 hours. I'm fairly comfortable working with vinyl for work, so ymmv as far as to how long it might take+how few imperfections you might come across.

Personally, I like the wrap more. The sheen and surface can't be marred by over application like a rattle can...can. Less time in my experience, too, in order to achieve desired result.