As a WDW vet, I highly recommend that you take a look at
HydroGuy's DLR Guide for WDW Vets.
http://www.disboards.com/threads/a-dlr-guide-for-wdw-vets.1162599/
Regarding the closures, yes, there are a number of headliners down for refurbishment, but it's not nearly "half the park." I took the list for Feb 23rd (as a guess of when you'd be going) and there are a number of big rides that are down, but the list looks worse than it is because it includes all of the shops, restaurants/counter service locations, and marginal stuff that normally aren't really even on people's radars of "must dos" (e.g., Blue Sky Cellar). As a WDW Vet, the biggest losses are probably Matterhorn, GRR (maybe, though you have Kali River Rapids, which is pretty close, just with a different theme), and World of Color. Soarin' is identical at Epcot, so you aren't missing out on that one (which a lot of people really like, but at least you aren't missing out on something unique to DLR).
Even with the closures, there are still a lot of fun things to do and (I think) plenty to make it worth a visit to DLR. At least you are aware of the closures, so you can decide whether you want to spend the money and visit the parks or wait and come back at some future date.