11-month contracts usually only work well for those who are fairly confident they don't want to renew their contract, or for those who hope to renew AND are being paid at a higher rate during paid months so as to be able to save for the month without pay.
Do NOT rely on any paid work during the unpaid month. If your employer runs an English camp and pay you well for it, great, but don't assume that's gonna happen.
10-month contracts typically don't pay during October but require the teacher to come back for the second term. Walk away from those employers and be glad you did.