Same here. Just make sure to set your inital shards correctly so that you can grow for a while. Once you have to increase shards you have to re-index :(. But that's fine. Just go with 4x or more the shards you need now and you'll be able to scale out to that many boxes.
it would be actually interesting and make the comment more useful if you'd share your own benchmark or real life anecdote about this, otherwise it's trollish.
(I'd expect performance between ES and Solr to be about the same and highly dependent on the underlying lucene engine)