This is an interesting question. I am dead set against putting stickers on MPs but Reprolabels has produced some stickers that actually do enhance some MP figures in a positive but subtle way. Although Reprolabels offers many stickers within each set, I hardly ever use them all. I pick and choose only the ones that I think help make the figure look better. In particular, I can recommend the following...
Soundwave - It's a must have IMO. The transparent stickers are not noticeable for the cassettes. I purposely did not apply the non-tranparent stickers on the cassettes. They were too obvious. As far as the figure, if you have the Hasbro Soundwave with the yellow visor, the red visor sticker is perfect to make it cartoon accurate. A few other minor stickers in the set (shoulders and knees) really look great. But I can't even begin to tell you how awesome the cassette stickers are. Check out the pics and see if you notice them. Oh and as a bonus, Reporlabels offered some cassette case stickers that are double sided, with hilarious song titles. Pure awesomeness.
Soundblaster MP-13B - same as above
The only other MP Reprolabel I purchased was MP-10 for my Hasbro MP Optimus Prime. I have yet to use them because honestly, I dont think this set enhances the Hasbro version of this figure at all. It's awesome as is. I might even sell this sticker set.
If there is any other set I might consider, it's Smokescreen. If you are interested in the racer look, a few extra sponsor badges might look good. But at the moment, I'm content with him as is.
Here are some pics. Note, my Soundwave is the Hasbro (yellow visor) version.
