We have been twice in June including this past June (15-21). It was crowded, especially due to the Pirates of the Caribbean movie premier they were having which caused all sorts of problems getting around the park. It can't have been too bad for us however since we are going back the exact same time frame in 2007! My best advice is to get to the parks at opening! You get so much more done in the first two hours than you can the rest of the day. If you don't know how to use fastpass make sure you read Hydroguy's tips on fastpass (do a seach using hydroguy and his many informatiave posts will come up, he should write a book). The nice thing about June is that the hours are longer, the nightly entertainment (fireworks, parades, Fantasmic!) run every night and there's just a lot going on to see and do. Slower times are great for short lines but you also have rides down for refurb, short hours and entertainment that if it happens at all will only be on the weekend. It can be hot but it can also be quite pleasant. DL is better in June than WDW is since there is little humidty. The other time we went in June it was cool and pleasant the whole time so you never know. I think if you go in with a plan, allow at least three full days (four is better), know fastpass and get there early each day and use Early Entry each day you can, you will be fine.
No info on that hotel. You might go to: www.tripadvisor.com They have great reviews by normal, average people that can be quite helpful.
Yes it is crowded in June. However, it isn't always hot. We had an unusually hot summer, starting early this year. Normally we also have "June Gloom" which normally doesn't burn off until the afternoon.
Even if it is hot during the day, our nights can drop 30-40 degrees. And it can be damp. No matter how hot it is during the day, be sure to bring long sleeves (and maybe pants) for the nightime.