Location Great, Green Initiative Better
We enjoyed our weekend visit at Palacio del Rio. I was there for a conference and brought my teenage son along. It's a clean, comfortable property with excellent location to the convention center (where my conference wasn't!) and it's right on the Riverwalk. I loved that the lower lobby access was restricted to hotel guests. I loved that the staff was extra attentive and patient.
We arrived really, really late with lots of stuff and my son wouldn't wake up. Both the bellman and the valet were patient as we collected ourselves.
The first day, the housekeeper was equally as patient with my son, who refused to get up. And she was very responsive to my request for a robe (Murphy's law: I didn't bring one, expecting one; was disappointed that there wasn't one, but asked and received!).
Finally, when we left, all members of staff didn't rush us out, helped us load up and offered directions and Sunday brunch recommendations. 
As for the room, I (we) found it to be very comfortable. The bed was cozy, room size was normal-to-just right, extra appointments were just right and the bathroom was nicely layed out and functional.
As with most hotels these days, water conservation is key so the usual steps are taken when it comes to changing out linens. The one green 'piece' that stood out was with the electricity. There is motion sensitive room lighting as well as the LED (maybe halogen) lights throughout the room and elsewhere on the property.
And, I don't know for sure, but I would venture to say the uber-cool elevators have some green stuff going on. Your kids will think the elevator system is cool, but it does take some getting used to. Instead of pushing the up/down button and getting in to choose your floor, floor choices are made on an LED panel in the waiting area and you are instructed via a voice response as to which elevator will whisk you to your floor. If you're not paying attention, you could miss it and end up playing with the system as we did once or twice. My teenager thought it was the neatest thing, even at 1:30 in the morning!
The short of it: if you don't mind paying a little extra and are looking for convenience and great service, Palacio del Rio is your place.
Warning: valet parking is $35+ per day (self parking didn't sound very convenient!)