Ok, know this is all about personal preferences, so here is mine. I've had campers for last 20 years, and found that carpeting is essential and that hard/rubber mats are not nice to live with in the main living area...
So I invested in brandrups carpeting (which is well designed, is secured so it can't move about, and doesn't curl up) PLUS the essential shaggy wool rug... This shaggy wool rug is the key. So let me explain.
I do a lot of trips out and weekend cycling events that often find one of us in the van dripping wet and freezing cold from being out in disgusting weather.
Firstly, when its wet, I found its better to soak up the wet rather than letting it sit on top of hard/rubber mats.. The shaggy rug is perfect for soaking it all up.
You take the rug out and hang it outside/in the house, to dry
When camping in cooler months, you want something nice to put cold feet on... A shaggy wool rug is perfect and homely... Everything else leaves us feeling cold.
When in sandy or gritty areas, you want something to capture all that grit and stop it being spread into the nooks and crannies of van.. The shaggy wool carpet catches an amazing amount of grit...
Just take the rug outside and shake it out each day.
Every evening when camping, you just fold the rug over, to make way for the bed to be laid out.
Every couple of weeks, I shake out the rug and stuff it into the washing machine... Comes out like new
Last weekend it even saved the day when a glass of red wine got knocked over.. Spilt all over my rug, which soaked it all up.. no stress
I love our rug... It makes life Simples