Yes, there are.
No, absolutely not.
With an LTC-A, you can purchase and possess large and non-large capacity handguns in MA and pre-ban, large capacity magazines (greater than 10 round capacity).
With an LTC-B, you can only purchase and possess non-large capacity handguns and non-large capacity magazines.
There is gray area about what is a large capacity handgun and what is non-large. But here are some examples:
Glock 17, 19, 21, 22, 23, 34, 35 - large capacity, requires an LTC-A
1911 - non-large capacity, requires an LTC-A or LTC-B
Kahr PM9 - non-large capacity, requires an LTC-A or LTC-B
The bottom line is that an LTC-B is horrible and greatly limits what handguns you can own. A restricted LTC-A is far, far better than an LTC-B.
You should check out the MA law section here to get more info and ask your questions there, rather than derail this thread:
http://www.northeastshooters.com/vbulletin/forums/81-Massachusetts-Laws