I am going to post a little different. I will point out a few things I think you should consider.
I have had a tent, TT, 5er, and several TCs. I have had 1/2-ton, 3/4-ton trucks and 1-ton. I started camping when my kids were about 4 and 5 years old. We also had a dog. The comfort level in each type of camping is without question an individual preference. It certainly depends on both the adults and kids. As you have expressed, only you can answer to what is crowded to you.
I have never purchased a new RV of any kind. I have only purchased one new auto in my lifetime. My point is, you need not buy either the RV or truck new. Most young couples with small kids are struggling to make ends meet. Whatever direction you choose, keep in mind there may be ongoing cost. I have known people with RVs that could not afford to go camping. Most people brush aside the licensing, insurance, storage and maintenance of RVs. After you get your RV, could you afford to have a slide repaired, fix a delam, buy four to ten (truck/trailer) tires?
My wife and I camped with 2 kids and a dog. My/our preference is with a used truck and TC. We never had payments and could afford to go camping. I see lots of nice trucks for 4 to 5 thousand dollars. I see many 3 to 5 thousand dollar TCs. In my opinion, you do not need a due1 ton or slide, and I would avoid a filon sided TC if I could.
I only unload my TC when I need my truck to haul something, which really is not often. I store my TC on my truck in front of my garage, and frequently use it for day trips. I seldom make reservations when I travel with the TC. I can afford a new truck and RV but choose not to. It allows me to afford other things.
I have a 1996 2500 Dodge truck and a 1988 Bigfoot (11.5 ft, non-slide) TC.
Wayne