Samoa was a great location. We were on the third floor, had a great view of the volcano pool, could see the lagoon and the Grand Ceremonial House. And, for you, running back and forth to Captain Cooks would be a breeze! I can't remember the room number, but I'll visit Tikiman's site and try to figure it out. Unfortunately, I don't know how to add pictures, or I'd show you the views! In any event, it was a fabulous location--great views, great people watching!
We loved the feel of the Poly...instant relaxation. The monorails and the boat transportation was awesome. Yes, I agree with your description of the bus service. Getting to MGM was such a feat (and there is no rhyme or reason to the queues...people just rush the bus. Luckily, getting to Epcot and the MK was such a breeze that the bus memory is almost wiped away!
The only real complaint I had with the Poly was with the housekeeping service. They were so understaffed, and a few times we'd return to the room at 2 or 3 o'clock and the room hadn't been cleaned. My son needed a nap so I'd just hunt down the mousekeepers and trade for clean towels. I really felt badly for the cleaners. They were working hard--the hotel was filled to capacity--they just needed more of them!
Other than that, it was such a wonderful experience that I really wish I could go back in August for the free dining. Last August we stayed in POR which was nice, but the buses really got to be a pain by the end of the week. (My son was in a stroller.) The Poly was just magical...I don't know if I could turn back!!! Ohanas and Kona Cafe two steps away...hard to beat. ( OK, I will concede that the food court at POR is MUCH better than Captain Cooks...no contest there!)
If you decide to take a walk on the wild side and try a new room location at the Poly, I give Samoa two thumbs up!

I think the rooms have been redone! Your girls would love people watching--lots to watch at the VP and on the paths to and from the GCH. The balcony was great for that!
Have fun!
I think I may have to change my screen name to greenwithenvy!!!