The Dalby D7 Vinyl Stabiliser is an example of everything that is wrong with audio today. The kings new clothes. If you examine the bottom you will see that it cannot improve the coupling of the record to the platter unless the platter or record mat is slightly concave. If the platter/mat is flat then it is effectively putting a little mass on the record label and nothing else. It does not change one iota the behaviour of the section of vinyl under the stylus. And yes I have heard it. Its value lies entirely in the bling bling world of exclusivity. No doubt you will hear a difference, but its minor and there are better ways to spend the money if improving your system is the primary goal.
In my experience if you want to deal with vinyl resonances then either
1) A well designed reflex clamp that is designed to couple the record to the platter via either a washer under the record ( e.g. Sota system ) or slightly concave mat ( Goldmund system )
2) Use a peripheral ring ( eg Micro Seiki, Clearaudio, TT Weights, VPi )
3) Use a heavy stabiliser in conjunction with a concave mat or a stabiliser that only contacts the outer edge of the record label and is designed to work in conjunction with a washer under the record.
4) Use a vacuum turntable system.