My thoughts, the 50 odd I have done have nearly all knocked spots of the very best stretches of UK roads, and most have way surpassed anything available at home.
Some have awesome scenery, others are just wonders of engineering or determination over geography, many are fantastic for most riders, others suit a certain pace or style of bike better than others.
None have left me wishing I was back home riding the congested roads of southern England.
I would never rate a pass on a 1-x basis.
The Stelvio is a victim of its own fame, most people want to tick it off a list, and it may dissapoint, but best to judge for yourself.
The Splugen has a fearsome reputation for the Italian sides numerous tight hairpins - but with that comes the most amazing road I have experienced in the Alps, it just goes straight up (or down) a vertical cliff.
Neither are much fun if you want to keep your R6 spinning to the redline and wear out some knee sliders, but surely any road with loads of corners, little traffic and beautiful scenery has to be good when your on holiday with nothing to do but ride your motorcycle.
If you want a flowing ride try the Fluella, the Splugen is the stunning one, least fun for blasting along, but most impressive and I feel very happy I took the time to ride it and for something in between try the Albula, if your in a major hurry use the Julier (Still amazing and better than any UK road I know of) - or do as we did and spend enough time to ride the lot