I promised a review of the YSS shocks, so after about 50 miles on them here are my initial thoughts. Are they better than stock? Yes, but not by the transformational amount I saw when I did the same upgrade on my Honda PCX 125. No down side, but I'd describe the improvements as noticeable without being outstanding.
Have they raised the ride height at the back? I think yes, but only by a cm or two. Cornering clearance does seem a little better as I tried hard and failed earlier to scrape the centre stand!
Do they soak up the bumps better. Yes. Now this is noticeable as I have tracked down some local well known bumpy roads and rather than losing any more fillings, I am finding the bump absorption to be much kinder on my coccyx! Seriously the old shocks were bottoming out on these bumps where the YSS are soaking them up. I'm still to test this aspect 2 up.
Worth the money? For me, yes as I was beginning to dread long rides on bumpy roads with all the punishment my back was taking. If you only ever ride silky smooth tarmac (but how many of us have that luxury?), then probably not.
Overall I'm glad I did the upgrade. Although the improvements are incremental, the way they tackle the rough tarmac has made it worth it for me.