Whichever sounds better / more to your taste. Sorry, that may sound unhelpful. But I never make decisions on technology. Any component is the product of the design vision and components. If you can't hear them then do a number of AI searches comparing the sound quality of the two. Read reviews.
I have an amp that operates in linear and triode mode (no secret Audio Research REF 160s). The difference is small but important... I always run it in triode mode. I would have still ended up with this amp even if it only had one mode.