We have a Renault Trafic Camoer conversion. Its a long wheelbase and as PP says above it really does make a difference in terms of space inside. We can sleep 4 but have never used the roofspace to sleep in, we have 2 in the van, one in the awning and teenager in his own pup tent which he much prefers.
Toilet is great for overnight/emergency wees but as it is in the main living area we never use it for number 2s! Always use campsite toilets and showers.
I love the pop top because it is so handy when you want to stand up to cook, get dressed, just generally have a bit more space when we're all in there on a rainy day.
We always use an awning for anything more than a couple of nights, we put a kitchen storage unit in there for the food and table and chairs for extra seating. We also keep clothes in the sleeping compartment of the awning, we all have our own bags, each person's bag contains smaller zip mesh bags with labels eg DS pants, DS socks. Sounds really anal but makes such a difference when you're trying ti grab clean clothes.
Other things I really love are the blackout curtains and cab cover, keeps the van really dark and cosy. A double fitted sheet over the bed at nighttime so you're not lying directly on the seating fabric.
If you can afford it I would recommend getting a solar panel fitted on the roof, we can now generate enough power to go off grid for a few nights which is fab.
Oh I really want to go away again now! Happy choosing and happy camping