I've tried both the 335 and 345, and I hands down like the 345 more. The extra diverter just means you can dial down/ up the flow of the jets a bit more in the 345, primarily due to it's layout.
I've never been a huge lounger type of guy either, however, I have sat in spas where they get the lounger seat right, and unfortunately, I don't think the 335 is one of them.