... I have stayed in a 2-bedroom at BWV and thoroughly enjoyed it. In my opinion, being in the Epcot resort area is equally as appealing as being on the monorail -- though for different reasons. I really love being able to walk or take a boat to both Epcot and MGM. It's also great having so many dining options available within walking distance (Epcot, Boardwalk, BC and YC, Swan and Dolphin). I also enjoy hopping over to Epcot for Illuminations whenever I feel like it! If you plan to spend most of your time at MK, I guess I'd give Poly equal consideration. If, however, you have lots of family of varying ages and interests, I'd pretty much rule out the Poly. Since you've already done the whole monorail resort thing, try something new -- I guarantee that you won't be disappointed!

I have 3 kids under the age of 9 and haven't had any interest in staying anywhere besides BCV... Even though we spend a few days at MK during our stay, we'd still prefer to stay in the Epcot area.
As far as daily maid service is concerned, you would get it if you booked your ressie through Disney reservations. If you rented points from a DVC member, however, you'd only get trash and towel service on the 4th day and then a complete room cleaning on the 7th day. That being said, you could also pay an additional charge once you get to BCV to have daily maid service. I can't recall what it would be for a GV, but it would be worth looking into if this is important to you.
IMO, staying at a DVC property doesn't at all feel like staying at home. The villas are beautifully appointed just like a hotel room, but you have the benefit of having a kitchen for quick meals (breakfast, snacks, etc.) and a private gathering place for all your family members. Of course, there's also the washer and dryer (which I always avoid!) and a wonderful whirlpool bath (which I'd love to enjoy more than I've done in the past!), which you don't get with a regular hotel room.
If you have any additional questions, don't hesitate to ask... I'm always happy to help!
Happy planning,
Sarah