My questions are these:
"Is sub-optimal routing caused by BGP so pervasive it needs to be addressed?"
that depends on your isp, and whether their routing policies (openness or closedness of peering, shortest vs. longest exit, respect for MEDs) are a good match for their technology/tools, skills/experience, and resources/headroom.
"Are these devices able to effectively address the need?"
some of the devices i've seen will address some of the weaknesses in some of the isp's i've seen. however, and more to what i think is the point here, none of the devices i've seen will make an isp better since (a) tools alone can't help, and (b) this isn't the tool that's missing. and now for the question you didn't ask... "why not?" controlling which paths you install based on any kind of observational or predictive metrics is theoretically only going to be as good as those metrics, which is usually not very good. but there's another limit, which is bgp path symmetry. most tcp implementations are still stone-aged compared to what the ietf recommends in terms of congestion avoidance and output timing, and are therefore pretty dependent on overall isochrony and on symmetric congestion/latency. let's say that you had ideal metrics for deciding which path to install -- your overall performance would then be limited by what other people chose to install as their path toward you. (experience says they're not going to trust your MEDs even if they're close enough to hear them.) -- Paul Vixie