I did for quite a while actually. I loved the social browser concept, but the fact that I couldn't get extensions like lastpass to work in Rockmelt killed it for me and drove me back to vanilla Chrome.

I still wished them well though, their product was good and their customer support was great. I'm sad to see the brand go away, but I'm pleased for them that they got acquired. Hopefully they go on to do well at Yahoo!

I don't use Rockmelt, but I did use Flickr and delicious. Yahoo is the touch of death for web applications and I've grown to resent their tendency to buy and ruin services I use. This case with Rockmelt is more of the same: I don't use it myself, but the people who do are now less likely to like Yahoo.