I have a pair of Retras and have zero plans to change them.
Yes, they are expensive, but they give out great light for wide angle and the aiming light works really well with the retra snoot.
My old YS-D1s served me well but I hear of too may problems with Sea and Sea these days, so I'd be tempted to look elsewhere if I were you
The backscatter flash looks decent but seems limited to macro and snooting, so for me its a choice of Retra, Inon 330 (my old Z240s did me good) and the new Marelux which I know nothing about
Mike