We have stayed at a DLH and PPH once each so I’ll weigh in on what we liked/loved and didn’t.
We booked DLH as a standard room using Orbitz. We were upgraded at check-in to a view of some kind, ( don’t remember exactly what it was called but it was the Frontierland Tower looking out over the central area where the pool/grounds are, maybe it was a pool view???). The room itself was absolutely amazingly fantastic. I loved every single little tiny detail about it. You just can’t beat the touches they have in there that make it classic Disney magical. For instance, pulling back the curtains to see the monorail slide a bit yonder and the Frontier Mickey floral right under our window. And I don’t know if there will be any finishing touch that compares to the DLH’s classic light-up fireworks headboards. The walk through DTD wasn’t bad at all and the security line at that end of DTD right next to the DLH grounds has never once been backed up, so that’s a definite plus. I will say the probability that a room is small does exist - I could totally see that, but our room that we had ourselves was nice and spacious. But IMHO worth it due to all the other pro’s that exist about the room.
As for PPH, we booked it as a part of an AP special that came with a Fastpass or two, discount and some (small like $20) dining credit. Because PPH also felt a little ‘meh’ to us too, we decided to spring for a park view room to increase the element of magic in our stay. At check-in we were upgraded to a 1 bedroom suite on a high floor and it was most definitely magical. The suite was gigantic (we only ever needed the bedroom and one bathroom part of it, but the gigantic living room suite and whole second bathroom were amazing and would’ve been awesome use of space with a larger group). The hotel itself is quite nice, but nothing about it (except if you have a theme park room) is especially magical and it doesn’t really have grounds to speak of and right now no real dining or restaurants either. You can absolutely watch World of Color from a theme park view room - we brought popcorn up to our room one night and watched it right from our window munching on the popcorn, the TV channel turned on to sync up the music. It was a very fantastic memory. I wouldn’t recommend it for your first viewing of it as the water screens were quite distorted/small/fuzzy and the scale of Word of Color is lost from that distance, but having enjoyed it many times from the pier, it was really neat to have this other opportunity/fun way of feeling very VIP in the comfort of our room watching the show go on below us. We did also very much enjoy our view (overlooking the Pixar Pier/Paradise Garden area of DCA). Our stay happened to coincide with one of the last RunDisney events at DL and so the morning of the run events, the pier was abuzz with the rides lit up and in motion (even with no people on them) just for the runners to enjoy (they were running the Fun Wheel/Pixar Pal-Around, Golden Zephyr and Jumpin’ Jellyfish with no one on them starting from 5am) and we saw the runners making their way through the pier area. Because of that extra activity and buzz in the morning, we extra enjoyed the view. But I’m sure waking up to a theme park view all still and quiet isn’t a bad deal either. It was also lots of fun to be in the park, and point over to our hotel and say “Oh yea, that’s where we’re at”. However, as close and visible as it was from inside the parks and as close as it “looks”, because there is no easy access park entrance for PPH on that side of DCA, the walk is a little long. Not much longer than DLH, but it can feel like a slog when you are tired. It should be noted that on the way to the parks, you must use the DTD security entrance closest to DLH that is somewhat long-ish, and there is absolutely no way you can cross the street and enter GCH to gain access to their much closer proximity to the parks. However, on the way out and back towards the hotel, you’re absolutely able to cut through the GCH and it’s a very nice shortcut to get you back to your room in quick order (unless you need something in DTD on your way back). So knowing that shortcut can help a lot, but it’s only available one-way.
For me personally, being in the room is so limited (because we like to be in parks open- close with sometimes a midday break just for rest/nap) that we really just need a clean space to safely lay everyone down and aren’t looking for much else. But that’s probably why we’ve only done on property twice in our many trips. I would tip towards DLH, but if you think you’d like PPH, then the theme park view is definitely the way to go and it’s a fine option, and like mentioned above, it probably only gets that ‘fine’ designation because the other 2 on-site options have so much more to offer in terms of their theme/charm/location and with the cost, many off-site options are at least on par if not better than what the PPH can provide (for example, while no hotel has ever given me quite that same view of DCA as PPH, there are many high-rise convention area hotels that can give the general feeling of still waking up to the theme park like being able to have a clear view of the Fun Wheel/Pixar Pal Around from the room- and those hotels are a fraction of the cost, about the same distance walking & depending on the chain may include some really nice breakfast options with my stay that is still far cheaper than what PPH would’ve been).