They actually rough up your nail, much like you would sand varnish before putting a second coat on. Mick, they might have used a power sander on you but they just used an emery board on me.

In my experience, Superglue is more brittle than acrylic. It seems to last for a while then come loose and shatter or crack. These acrylics seem to last forever if you get them filled.

If you don't get them filled, it might be best to just have them removed. They loosen at the base. Eventually they'll come off and probably take layers of your nail as well as the tip.