Flat vs Round Rings, Whats Your Experience?

What exactly do you mean by "flat" and "round" base rings?
By flat, do you mean that if you put one on a flat surface, all points of the ring would be in contact with the flat surface?
Or do you mean that the cross section of the ring has flat surfaces (like a square)?
By "round", do you mean the cross section of the base ring is circular?
Or do you mean that the base ring is somewhat curved (like a potato chip/Pringle), to fit more ergonomically to the wearer?

My experience of 'flat' (square cross section) base rings is that they are very uncomfortable.

My experience of flat (all points in contact with a flat surface) is very good. Sometimes the curved (ergonomic) type can be too curved, and thereby feel uncomfortable.

So, for me, I prefer a flatter base ring with a round cross section for maximum comfort.

 

I have also worn base rings that are perfect circles, whereas my last base ring was oval or egg-shaped. I found that it was the most comfortable base ring, because it was wider at the top. My current, ergonomic (not in contact with all points on a flat surface) is ok, but it is circular rather than ovoid when viewed from 'above' (if lying on a table top, for example). This adds pressure on the sides of my scrotum, but is probably a consequence of wearing a broader base ring before this one. I expect my body will conform to the new shape eventually.

 

It's ok.
The limitations of words over images.

 

In my experience, only perfect round circle rings DON'T cause any problems. Circle rings that are not rounded make me chafe, while oval/irregular shape rings cause my balls to cramp up. Thing is, you just don't know until you try and I tried all 3 types I just described.

 

While almost half the weight of a typical steel cage my titanium BAW is still almost twice the weight of a typical plastic cage. My titanium cage still slips occasionally and if I had it to do again I’d close the ball gap tighter to help with the slippage. If you aren’t familiar with that measurement it is the internal gap between the cage and base ring that essentially grips your ball sack. Obviously you don’t want to crush yourself here but definitely snug and firm is better for keeping the typical cage sag from happening.