The Rustler 9 is the narrowest of the 3-member Rustler family, at 92mm underfoot. The Rustlers 10 and 11 are 102mm and 112mm respectively, and the dimensions alone should indicate this is a freeride-biased family. But the Rustler 9 is aimed at a recreational level of skiing and isn't up to out-and-out off-piste charging, so we've assessed it as all-mountain.
On the subject of waist size, the Rustler family has adopted the useful approach of increasing width along with length, which should help ensure the skis perform consistently across the range of sizes: So the Rustler 9 at 188 has a 94mm waist, rather than the 92mm of the shorter lengths.
On the mountain, the Rustler 9 turns out to be a very solid ski and performs pretty much as billed without being hugely remarkable. It is fun, poppy and bouncy in the cut-up off-piste snow - perhaps more stable than the 'recreational' badge might suggest. It isn't the easiest ski to turn, but given the lack of sidecut it is highly manoeuvrable if pushed.
Strangely (for a recreational ski) the Rustler 9 excels when it is cranked up; it's solid in fast GS turns on hardpack, and equally so in long, sweeping freeride turns. The Rustler 9 could easily be classed in the advanced/freeride category.
The plus side of this for the recreational all-mountain skier is that it offers room for improvement, meaning you won't quickly out-grow the ski's capability.