My first two trips I got a great deal upgrading from Pop to CBR...
If it's within a few hundred dollars, I think it's worth it, but that's my personal choice.
With respect to All Stars vs Pop, I've not stayed in the All Stars, but my sister has and I've walked the grounds...
I'd do Pop, for one primary reason. Busses.
1) It has it's own dedicated bus service (the All Stars share)
2) You can also use the AoA bus (very convenient after a long day at the parks, or if you want to eat at the AoA food court to try something different than Pop and then head out to the parks.
If you are not planning on using the busses, the benefits drop away, obviously.
But, if you can get a good deal on CBR or POFQ or POR...I'd do any of those resorts any day over the Values, with the exception of a family suite at AoA possibly...
We will be using the Disney busses. After all, we will be on vacation and my dad used to be a city bus driver in Montreal for 23 years so I'm sure he'd like to compare the busses back home with the ones at Disney. LOL!
I appreciate very much your responses.