I went through exactly what you have described about two years ago. Went from a 25 foot 5k lb trailer to a 35 ft 8k trailer with a 2009 F150. One trip with the new trailer and I decided to get a used 2011 F250 6.2 gas. It does a lot better job and I look forward to our trips. Not to say that I couldn't have towed with the half ton (I would have been over payload though because the 920 lb factory tongue weight was 1,230 once loaded) I just didn't like the way it felt. I had an equilizer setup, so it wasn't the best hitch system, but it works great on the 3/4 ton. Folks tow more than I have with a half ton, I've seen it and I'm glad it works for them, there is no right or wrong here. If your able to get a bigger truck I don't think you'll regret it one bit.
Happy camping
