I've been using 80 legs heavily for the last 6 weeks. I've held off a blog post to give them a chance to fix some issues I've hit, but overall they're an awesome service.
A massive plus is their helpfulness. Shion, who commented on this post, even wrote a bunch of custom code for me!
An interesting development might be the emergence of services that effectively function as 80legs resellers. Shortly after 80legs's debut, some guys from my company approached a vendor at a conference who offered SEO-focused crawling services. The tool is in alpha and we are still waiting for an invite, but based on the data points that this tool is capable of harvesting, as well as the price point (very similar to 80legs) I began to suspect that their custom code relies on the 80legs backend.