One of my favorite trails to test bikes on here in Bellingham is called Dad Bod, a descent full of quick dips and dives, with plenty of sideways roots and off-camber bits to keep you on your toes. It's not the absolute steepest trail, but it's a great way to see how well a bike maintains speed and responds to quick direction changes. The Spectral felt right at home in this setting - the 150mm of rear travel is well managed, with enough support to keep the bike from feeling mushy or lethargic when pumping the backside of a roller or pushing into a turn, and the ability to take the edge off bumps without completely muting the trail.
Frame stiffness is always a tricky thing to judge, but I'd put the Spectral towards the stiffer end of the spectrum. It has a more taut, almost 'pingy' feel, for lack of a better term, compared to the Transition Sentinel, which has a slightly softer, more compliant feel.
On rougher, steeper trails the Spectral still maintained its composure, but it doesn't really encourage the same level of reckless abandon as a bike like the new Commencal Meta TR. The Meta, even with less rear travel, has a more planted, plow-through-everything nature. If the Meta is an aluminum meat tenderizer, hell-bent on smashing the trail into submission, then the Spectral is a finely honed chef's knife, precisely slicing its way down the fall line.
The Spectral's limits feel a little more defined – it does exactly what it's designed to do, but I also never found myself wondering about how it would handle with something like a 170mm Zeb up front and a coil shock in the back. The precise, agile nature of the bike makes it seem like trying to beef if up would be a step in the wrong direction. As an aggressive trail / all-mountain bike it hits the mark, but it's not quite the gravity fiend that enduro racers may be looking for.