We stayed here for a quick overnight June 20, 2013. The Splatter Rock cabin was perfect for the 2 of us, as we needed room to spread out and re-pack our camping gear. Friendly hosts, clean room and a very nice kitchen/dining area in the Octagon make this place a comfortable choice. Bathrooms are outside in a separate building, be aware - but you know it's a hostel, right? I think they have a terrific and informative website, too.
They are right next to Carlo Creek; great for ambience, not so great for mosquitoes, especially in mid-June. However, you have to know that going to Alaska in early summer is bug season, so come prepared with repellant and a head net. We did experience a bit of road noise from the cabin. It was unseasonably hot during our visit so we had all the windows open. I'd imagine it would be quiet with them closed. Be aware you can't park your car at your cabin. It is a short walk, however, and they do allow you to unload your luggage before re-parking.
The hostel is located 13 miles south of the park entrance, away from the congestion which was nice. The Creekside Cafe across the highway is a good place for a meal and also provides box lunches. If your budget allows, plan a dinner at Parks 229, 5 miles towards the park entrance - it was excellent.