Hello, I also have a 5m Soulpad hybrid (with ZIG) and I love it!
It does seem huge but the feeling of light and space inside it is amazing. There are 3 of us and I think if we'd gone for the 4m it would have been cramped. However I am a maximalist (gl)camper!
We have the Belltent.com tealight chandelier, and have used it with both real candles and electric tealights. In my opinion it didn't really make the tent appreciably warmer when we used real candles (wet drizzly week in Cornwall) although it did make the tealight chandelier itself rather hot when it came to lowering it to blow them out! So now we stick to electric tealights for safety, the pretty look of it and a bit of ambient lighting. It does pack away very flat.
The one thing I would say is that you need to be very organised and have storage you can chuck stuff into otherwise it can look very messy very quickly - we have a low-level long camping cupboard with a hard top that we use for clothes and put other bits n' bobs on top of it (mirror & hair stuff etc. at one end, teatray at the other). Then we have a collapsible faux leather ottoman that sits at the end of the beds and holds dry food, a pop up bin (toy storage from IKEA with a bin bag inside it) and a couple of folding plastic crates, one by the door for shoes/wellies (used to transport kitchen stuff on the way down) and one for DD's toys & books. Next to our beds we have 2 little lidded boxes that go in the footwell of the car and are big enough to contain useful stuff like a paperback/kindle, torch, first aid kit etc. We stick little lanterns on them and use them as bedside tables (I wear glasses so I need somewhere to put them at night!). Outside we've got the camp cooker on a storage unit that everything else goes into next to the Icey-tek for cold food. This goes under a matching tarp that we got from Oberlink away from the tent with the firebucket etc. I have far too much a lot of collapsible & multi purpose stuff!
The floor does get very cold although it's never leaked or let in damp. We have a rug (not a made to measure one which are £££, just a standard rectangle one) which lets us keep bare feet warm inside.
Be warned, bell tents are a gateway drug to bunting and other glampiness :o