Agree, it's a huge transformation - I really like it from what I've seen. I do think there is something in the view that a clean/simple house that is more appealing to look at is less likely to detract viewers. Look at Love Island. The villa is so sleek and modern, it just looks great on screen. Whilst the BB18 house was a great design, it didn't look "appealing".
Very impressed with this, here's hoping a series to match!