This is obviously a small form, but imagine it has lots of fields for a registration form for example. On a larger form the parser would be dipping in and out of and between html and php whereas for the second one it has more to output but hasn’t got to start, stop sort of speak.
The difference is so small that it’s irrelevant - but you can run your own benchmarks if you really want to know :). Think about which one looks cleaner and is easier to maintain. If you output html in php template files then most people would use the first version because such files are more html than php and you get all the benefits of html syntax highlighting in your editor if you drop out of the php mode - whereas html in echo is just a string of plain text. The best solution, I think, is to use the short php tags:
Be careful with short tags, they are not always enabled, and keep in mind they can be disabled. Not that there is anything fundamentally wrong with them, just keep that in mind.
I must admit, I tend to echo all my html, but I must add that using short tags does make the code easier to read and saves a lot fiddling around if you want to copy the html code into an html file - I thinks it’s down to personal preference really. I’ve never come across a server where short tags are disabled though.