I can shed some light, albeit limited, on the Altras since I just bought a pair and decided to take the Trailrunners In the Wilderness Challenge. So far I'm loving the roomy fit, especially in the toe box, and zero rise. They're definitely ruggedized feeling and lack the flimsiness of barefoot shoes. Rocks underfoot are no problem and I was surprised (and wasn't expecting much) by the efficacy of the rock guard sandwiched in the sole.
But more to the point of use in cooler temps; the breathability is, at least for me, going to necessitate some different sock choices. Last weekend during some 50-60* sunny afternoon strolling over several miles of the most brutal Texas Renaissance Festival terrain (read: a field) I had chilly toes while wearing my newly purchased merino blend (with acrylic) mid weight hiking socks. I'm going to need warmer socks for sure, and not necessarily thicker since the mesh body of the Altras is pretty stretchy and requires a substantial amount of tension on the laces to lock the shoe onto my foot for rougher terrain.
Additionally, I can attest to them being absolutely positively NOT at all water resistant even in damp grass. While I can appreciate that while some of these guys are 30 miles from the nearest road in BFE sharing a cigar with local woodland creatures, everyone in awe of the natural beauty laid out before them, that wet feet might well be offset by the awesomeness of the circumstances, BUT it's pretty godd@mn annoying to take the dog out at 1am to do his dog business and come back with cold wet toes. I'll be investigating the neoprene sock and gtx sock options for actual backpacking trips ASAP since even down here in the south, cooler weather is upon us.