Elementary is pretty old tech, it comes with kernel 3.2, which is basically defunct on PC's.
The performance, especially in terms of filesystem features and performance, scheduling, power management and advanced graphics performance, suffers too much for it to be an interesting distro for desktop PC use.
If you want Debian, don't go for a bloatware spin-off like elementary, just go for the real thing, and go for Debian Testing branch, it's up-to-date enough to have good performance and features, and you still have all the options open source is so great for, whilst keeping the system as lightweight as possible for the configuration you want.
If you want close to Debian, and good medium-modern performance, go for Xubuntu, it'll be a whole lot faster than elementary, have more features, and be easy to set up and configure to your liking.
If you want the best possible performance and better XFS support and better power management and support for the latest GPU's and UEFI's, go for a bleeding edge distro. A lot of gaming users really like Manjaro, which comes preconfigured with Steam and has support for proprietary graphics drivers, it's pretty lightweight for being full-featured, it's fast and stable as it is based on Arch, and it comes with native software center support for the Arch User Respository, which means that a lot more software is readily and easily available.
I'm just not sure that there is a real market for elementary, it just seems like a wanna-be-Windows type of linux project, that is limiting instead of expanding the possibilities of open source and linux.