Hi Elizabeth - After reading your sentence, "...And I also now have to go stock up on my action gallery...", I realized that we probably are not talking about the same thing. The title of this thread is about actions, in general, whereas I'm starting to think that you are really asking about actions that have been developed by someone else, eg, commercial actions that one purchases.
I use actions that I've developed for myself with some frequency, but I almost never use actions developed by someone else. In fact, I haven't had any commercial actions installed on my machine for the last several generations of PS.
The reasons are:
(a) I always wind up needing tweak actions developed by others to fit each image to which I want to apply that action. The time it takes me to tweak someone else's action is just about the same, if not longer than the time it takes me to develop an action for myself, from scratch, that does exactly what I want, right out of the starting gate.
(b) In the last 5 or so years, the actions that I develop for myself have tended to be for mundane tasks like adding a thin keyline just inside the border of an image, or stacking together several different layer effects (...which can now be done without actions in PS CC 2015), or producing several different sizes of a particular image, etc., BUT NOT for color and tonality type changes, which, historically were always the most popular type of commercial actions.
(c) Lightroom's wonderful management of ACR presets and the convenience LR brings to the process of exporting an image to various types and sizes of files, as well as all the options it offers for printing has dramatically reduced my need for actions within PS to perform such tasks.
Another question that could be asked is whether I think people starting out in the photography business and post processing should rely on commercial actions. My answer to that is, "no". The reason for this is that since one almost always has to tweak a commercial action to get the best out of it, the novice Photoshopper has to know whether he/she should adjust the opacity or other parameters of one step, of several steps, introduce other steps, etc. etc. If he/she doesn't know exactly what to do, they'll never get the best out of commercial actions. If you don't have these skills, the novice Photoshopper will be reduced to going through long lists of actions just to find one that works well on a particular image. You won't learn anything from this process except the obscure names of the commercial actions that you own. OTOH, if you develop a deep knowledge of fundamental PS skills, it will be your choice whether you want to tweak someone else's action or just make a new one up for yourself whenever needed.
So, to reiterate the answer to your initial question about actions, in general, I will use *anything* that speeds up my work including actions (both commercial and my own), other software (eg, Lightroom), and most importantly, plugins and plugin suites like NIK's Color Efx Pro, all the wonderful Topaz plugins, etc.
I hope that clarifies my answer.
Best regards,
Tom M