I have used both B plan types of sail the current loose footed is a bit better, than the bolt roped boom version.
I am a light weight 9.5 st 6ft 62 year old . I do join in with some open meetings and championships. I have opted to sail B plan in windy conditions knowing that i will get a good sail , better than no sail after travelling and overnighting. The down wind legs are fine and i dont lose out much, but the long up wind legs are really slow and frustrating watching most others disappear! I have retired from races so as not to delay the next start, as i have been so far behind!!
If you do get a sail cut down i advise you on getting a window fitted in it.
I do go cruising and the B plan is great - i have had a old full sail fitted with reefing lines which also works fine for pottering.
Regards Bill Hutchings