We're running the Abbey Road Plug-ins RS 135 and the full Brilliance Pack at the studio where I work on a few different Pro Tools HD systems. Running it on this system isn't a good judge of how much processing power plug-ins will take up, as they can handle pretty much anything since they're HD systems. However, I'd definitely be surprised if many users had problems running this plug-in since it's such a simple one.
Although limited in what it can do, the Abbey Road Plug-ins RS 135 is great for adding a little bit of brightness to your sound. It's a really warm sounding plug-in, which is really the main reason I like using this for boosting at 8 K rather than using a more traditional parametric or graphic EQ. I love using this on guitars mostly, but even for vocals if I feel the timbre could use a little bit of high end color. This and the other plug-ins in the brilliance pack are great for both mixing and mastering, so definitely check them out if you're looking to add some new high quality plug-ins to your DAW.