Don't have an awfull lot of experience, as I only started painting my nails about a year ago! Now I have a whole load of LD and Nails inc. I love the colours in both, and there staying powere on my toes is 2 weeks. After that I have to redoo as my nails grow too fast not to. On my hands none last much more than 24 hours, but I think thats the kind of person I am, rather than quality.
I went for nails inc, because my nails went to peices when I started at the begining of the year, and the nails inc treatment base coats got them sorted. I also have a nails inc topcoat from superdrug and it dries so much quicker that the LD crystal finish. Didn't like the lids much to start with but having followed AY's advice from a nails inc prog I get on fine with them now.
The other reason is the quality of the Nails inc tsv was much more in line with the other bits I have, than the LD one was. LD's other polishes seam much better than the ones in the TSV at the begining of the year.