I've had a $15 prepaid base plan for some time, using non-expiring booster packs for talk and data. I was looking at the available plans today and I see that there's now a $15 plan that includes 250 MB/month of (expiring) data. Do I lose anything by switching to that just before my next bill? Will it use up the 250 MB and then start using my booster packs? If there's no disadvantage of that plan, why do they have both?