MLW,
I never buy the all in one plastic frames just because of the slots in the frames. I do use plasticicell foundation and it works very well if you use all plastic in any individual super. When it is all they have, they build on it very well and 99% of the time very neat. The only problem I have with it is that it is 5.4 MM instaed of 4.9 MM which is what I want in the brood box.
Jim