Question about top hats for aftermarket coilovers
 

I’m having a used set of AST 5100s rebuilt. As I wait, I’m trying to complete all accompanying suspension bits but running on a budget. What are the pros and cons of using stock vs stiffer sti/group n vs pillow ball top mounts? Car is currently 50% daily, 25% canyon, and 25% track. Am I stopping the whole potential of the struts if don’t go for the pillowball top mounts? Tire and wheel choice is 17x9 gt radial sx2 square. Trying to get the optimum drop 0.75-1 inch. Thanks in advance for your insight and advice.

Pillow ball require more maintenance and have a shorter life span.

With aftermarket top hats you can adjust camber from the top if you need more than the lower strut mounting point can give, that is if the bottom of the front struts are adjustable/slotted.

I'm not a fan of pillow ball joints on a road car if I can avoid using them.

There is little NVH change vs stiffer rubber topmounts like group-n/sti/trd ones vs stock. Then again there is not that much to be gained either, and if switching to such, i'd rather think of gaining something else too, not just stiffer rubber, for example - extra camber from eccentric rubber topmounts such as from Pedders.
Camberplates with pillowball may add more NVH (though it may differ between different camberplates or different coilovers & camberplates sets. For many users report no untolerable NVH issues and that all is fine too). In salted winter environments there also might be more issues with long-term use. If there is choice between pillowball camplates or rubber topmounts, i prefer later, due experienced NVH issues with combo of stock shocks+raceseng plates. But if there is such choice for your mentioned ASTs 5100 at all, i don't know. Some coilovers cannot be used with stock-like rubber topmounts, only with camberplates in set.