As per the section on Gear above, there is no shortage of advice and opinions, and human nature dictates that whatever you have, you will want something else.
The Hookway family did the first 12 months in a 20 foot caravan with ensuite, bunks, instant gas hot water, air conditioner and full length enclosed awning. While the kids were little they said it was great having a shower inside, and if the weather was bad they could just pull up, open the door and carry them from the car out of the weather. For them, the advantages were it ease and speed to set up and comfort once on site.
But it was enormous to tow, heavy, slow, increased fuel consumption considerably, a pain to manoeuvre and park in towns, tight caravan parks and bush campsites, and generally increased the stress of driving.
They then traded to a 14 foot wind up camper with slide out beds. This was much easier to tow, faster, much more economical, very easy to park and manoeuvre. But it took longer to set up, had no shower, was drafty in the cold weather, canvas leaked and felt like the roof was going to blow off in wind.
Regardless of what you are in, the weather is what makes the trip enjoyable or miserable.