Im obviously biased but I prefer clients that don’t require extensions to the protocol for it to work, if their caching servers go down for instance. With primal you get ux gains but it makes the entire system more brittle. Primal has a huge advantage with its built-in wallet, but damus has an advantage in countries where that wallet is not allowed. Just use what feels best to you, but keep in mind the tradeoffs that are being made.

I use primal, the one con I see is that primal fails to fetch some data, some notes, likes and zaps, I usually use primal in posting notes but in viewing and checking notes, zaps and replies I use other clients, mostly amethyst though.