I actually downgraded from the Shelter 90x to the Dynavector XX2 mk II. Big mistake. I have a nice sounding vinyl rig but the magic was lost went I downsized on the cart. I think you are going to be thrilled with any of those 3. If it were me I'd get the Harmony since I know how great the 90X sounded. I went kind of crazy and started freaking out about surface noise and though the 90X was more prone to picking it up and remembered back to some of the lower Dynavector carts and was thinking I wasn't bothered so I jumped ship.
Bottom line is there is a reason those carts cost so much. Because they are worth it.
Bottom line is there is a reason those carts cost so much. Because they are worth it.