Hi Giuseppe, I have not had an Elddis either but the people who I bought my motorhome off bought an Elddis brand new as a replacement, they only live up the road from me and the only complaint they have ever voiced to me is that the shower/toilet cubical is small, but saying that ours is huge and I think they just got used to the extra space we now have.
As for generators or solar panels they are fine and will serve a purpose, however if you buy a van without either my advice is to try it lots first, we are a family of 4 and do not have solar or a generator and I can park up for 4 days and nights without starting the engine without any issues, on the 5th day the power gets a bit low, but its rare we sit in one place that long anyway.
But it all depends on your power usage etc.
Rolling on and enjoying life on the road