No other brand of ergonomic grips is as widely marketed as Ergon, so it can be harder to gather opinions on them in comparison. I have been using ergonomic grips on practically all bikes, for a long time, went through many of them and learned to avoid Ergon. It might be helpful to explain why.
Metal is harsh to grab for a hand. Aside from hardness, in colder weather metal drains heat from bare hand. Yet Ergon persist with a wide metal band on the side of the grips, presumably because it gives them a characteristic look good for marketing, consuming valuable handlebar space. Brompton M-bars have particularly limited straight bar space for use. In the grips. the top that gets press wears faster than the bottom. When the grips are top-bottom symmetric, you can swap the right with left and double the life of the grips. Yet Ergons are top-bottom asymmetric that brings in little in comfort but makes consumer go through the grips twice as fast. When you fold Brompton, the ergonomic grips can add ~1cm in transverse size that can make the bike harder to squeeze into a rigid case such as B&W. The ergonomic shape can be built up out of rubber and then you just squeeze the shape and fit the case. However Ergon build their shape on a rigid substrate that cannot be squeezed.
My favorite grips are the inexpensive Sunlite Ergo, that have all the features I want and are easily available in US. However, in Europe they may be marketed under another name. Of course there are other features of the grips that are important and the grips can be generally difficult to assess without grabbing them and even putting on, such as whether they are not too hard or too slippery.