Mutagen, as warden is mostly heals over time, there is a risk and this provides insurance.
GrumpyDuckling wrote: »Mutagen, as warden is mostly heals over time, there is a risk and this provides insurance.
I agree with Tasear's comment^
The only exception to Mutagen over Rapid Regen may be if you're relying on a Maelstrom Resto staff for magicka sustain, because then you'll get more consistent sustain from the speed of Rapid Regen.
There are lots of threads on this topic, so give it a search. But to argue my point as a healer with 10 years experience in MMO's, it all comes down to healing output and predictability.
Rapid regen offers a higher output of HPS (heals per second). HoTs (heal over time) are used as a buffer, NOT a lifesaver. You stack HoTs during downtime, so when the burst "oh ***!" moment hits you, there is some instant regeneration which gives you time to use a specific "oh ***" heal, such as Enchanted Growth or Healing Ward for a Warden.
You want a predictable HoT, that is programmed into muscle memory (this HoT ends at X time) due to the fact that this game is not built around targeted heals and HoT tracking. The problem with Mutagen is it could be consumed at any time due to damage, at which point you must then recast mutagen, as well as hit that "oh ***!" heal. This is not good for your output, especially considering two ticks of Rapid Regen = final tick of Mutagen.
With this in mind, Rapid Regeneration has a higher average output due to the fact that the heals are always triggered, unlike Mutagen which requires a significant drop in HP. Rapid Regen is also more predictable as it is only consumed due to death or duration.