I'm unclear as to what benefits I get from EBS vs. instance-store for my instances on Amazon EC2. If anything, it seems that EBS is way more useful (stop, start, persist + better speed) at relatively little difference in cost...? Also, is there any metric as to whether more people are using EBS now that it's available, considering it is still relatively new?
I'm just starting to use EC2 myself so not an expert, but Amazon's own documentation says:
we recommend that you use the local instance store for temporary data and, for data requiring a higher level of durability, we recommend using Amazon EBS volumes or backing up the data to Amazon S3.
Emphasis mine.
I do more data analysis than web hosting, so persistence doesn't matter as much to me as it might for a web site. Given the distinction made by Amazon itself, I wouldn't assume that EBS is right for everyone.
I'll try to remember to weigh in again after I've used both.