No, you won't regret it. Honestly, the bus thing is such a non-issue but so many people make a big deal out of it. Truth is that you won't always share buses. At the busiest times, you'll have your own bus. Other times, yes, you might share and it might add a whopping 5 minutes to your commute time. That's about it. On the other hand, Pop has twice as many people at the resort. So even though you'll have dedicated buses, there's a WHOLE lot more people trying to get on those buses.
I've stayed at both, as well as AS Sports, and would choose either of the All Stars over Pop any day. Because Pop has so much bigger, the food court, gift shop, lobby, etc., just always seemed crowded and chaotic. Especially the food court!