I used the Jenter system for the first time this year and was delighted with the results. Have tried the imitation Nicot ones from China and not been impressed with the results. Jenter seems to have the build quality (although it comes with a very hefty price tag)
Yes both Jenter and Nicot are very restrictive in terms of timing and being lucky with the weather but for someone with less than 20/20 vision for grafting these solutions are excellent.
Only really needed a four or so queens but ended up 23 cells which translated into 15 successfully mated queens (I'm happy with a 65% mating rate given the atrocious weather period here in Gizzy in the two weeks from when they emerged).