I started in Limited minor because I had an M&P setup for IDPA ESP and thats were it fit. Made it to the top 20 classification list of B class. Switched to Limited Major with an STI Edge and made M in about 4 months.
Shoot whatever makes you happy and will keep you shooting, wether that is chasing the heat in whatever division brings the most locally, or what ever fits your fancy for speed or accuracy, etc.