I'm still very much a fan of a low profile glue in machine style bolt for a range of routes. It'll come down to a route by route judgement. However, for me anything where the 'obviousness' of a line of rings alters the commitment of a route - either when you're on it, or standing down the bottom gearing up for the onsight - I'd prefer to keep it on low profile hex heads.
Climbing at the county on the weekend carrots seemed appropriate for 80 minute hour - you can clip most of them from good stances, but you've got to climb to them before they are obvious. The rings worked on Walking Wounded. I'm not sure I'd have much of an opinion either way for Mindblower as the gear is pretty clear from the ground, but the carrots on Barbarossa definitely added to the experience. It added to the sense of commitment, and the need for mental control that defines this style of climbing - even if it isn't exactly a chop route - and for me that was valuable.
My 2c:
Steep and pumpy thugfest - ring it
Regularly dogged & redpointed, rings probably make more sense
Classic blueys wall climbing - probably machine bolts
Mixed adventure route - glue in machine style bolt