We haven't stayed at BLT, but we have stayed at BCV and BWV.
BWV has my favorite views of any of the resorts. (I haven't had the MK view at BLT overnight, however I've hung out a little at a fellow DVCers room and seen the view. The amount of parking lot puts it slightly below BWV for me.) I absolutely love the Boardwalk view at BWV. If I'm going at a time I know I'll have to spend a fair amount of time in the room (we have a toddler right now, we're generally in the rooms a lot for nap time), I generally go for BWV (or AKV.) The people watching from the Boardwalk view rooms is great, as is the view towards Epcot. We love watching the Illuminations fireworks on our balcony in the evening. No, you can't see the whole show because of the trees in the way, but you can see a sizable portion of the fireworks.
We also love that you can walk fairly easily to DHS or Epcot. We generally seem to just miss the boats (seriously, I have the worst boat karma), so we almost always walk. It's about 15 minutes to DHS and just under 10 to Epcot at our fairly leisurely pace. We always see assorted wildlife on our walk to DHS, usually a lot of birds, some fish, and bunnies, and there were trips that this excited some of our party.
The boardwalk itself is really sort of treat in the evening. We love the street performers and the energy of it, and we sometimes sit on our balconies and watch from above. The lake and boardwalk area are peaceful and beautiful in the morning, so we like to sit on the balcony and sip our coffee and take in the atmosphere. These really add to our enjoyment of our trip, but if you're not someone who sits and relaxes on your balcony, obviously, they're none issues.
Now for some BWV negatives. The long corridors at the BWV are a major negative. They are definitely the biggest downside for me. They are too long, and I don't like the new carpet and wall coverings from a few years ago. It seems too generic to me. I also don't like the pool much. The clown slide is the stuff of nightmares visually for me. The elephants are cute enough. I wish it was zero entry for the kids. If they would just do a serious overhaul of the pool area, get rid of the evil clown, make it zero entry, and do some sort of water play area, I would be much much happier.
BCV rooms generally have no view to speak of. This bothers me a bit when I am occasionally stuck in the room. On the other hand, they don't have the crazy long hallways serviced only by a single elevator lobby that BWV does, and it is closer and easier to refill you refillable mugs, if you happen to buy them at BCV. The big draws for me are the pool, of course, and the ease of the walk to Epcot.
More little things... I like the BCV lobby better. It feels both more comfortable and more expansive. I like the smell of the BC lobby better. (Yeah, I know that sounds weird.) I have found BCV to be quieter than BWV at night for sleeping.
I don't love the modern feel of the decor at BLT, which feels a little like any upscale hotel you stay at with modern Disney art. I prefer both BCV and BWV, just because they feel a little less generic to me.
Transportation - haven't stayed at BLT, only visited, but I've stayed at monorail hotels and love the convenience for MK and to a lesser extent for Epcot. The buses at both BCV and BWV can be a bit of a pain, as both (more often BW) sometimes share with Swan and Dolphin. We haven't found the buses to be as crowded heading to the parks as we have at other
DVC resorts. That may not be consistently true for everyone, but it has been more often than not for us. (The buses for AKV and SSR always have been mobbed, and seating room seemed to be at a premium in both directions.) BC gets a slight edge, since they seem to share buses with the other resorts a little less often.
We love the Epcot resort area, and we love to go for Food & Wine, so we knew we wanted to own either BCV or BWV. We chose BWV because we wanted to be able to book those boardwalk view rooms, we wanted potential access to the grand villas (which BC does not have), and because we wanted to be able to walk fairly easily to both DHS and Epcot.
I hope some of this is useful.