It entirely depends on price and your urgency.
Given that 7a will be coming out shortly, I advice you to wait a month until it comes out. Once out you'll know the exact price and specs/performance. Also it will cause the price of the 6a and the 7 to drop as well. Then you will have a better comparison point.
IMO the 7a might be worth an extra 100-120 USD, but probably no more. Ultimately its "you" that has to decide whats worth what to you.
Price IMO is that big deciding factor.