Its just like anything else you buy. Find a refrigerator, tv, hotel and read the reviews. If there are 500 reviews: 250 hate it and 250 love it. So don't let other peoples' opinions sway you.

 

Go test ride the different models.
Having had many metrics, bought the SGS and love it. However the ultras ride much more smoothly so if you need a very smooth ride get an ultra with the removable TP and get the best of both worlds.
Still I would not trade my SGS as I enjoy the handling and feel of the bike.
Hope this helps