Re: What's so great about a pro horn?
'Student', 'Intermediate', and 'Pro' instruments are designations placed by the manufacturer to distinguish model lines and are otherwise completely arbitrary. You may indeed find Intermediate horns that out play and out handle some other horns that are considered pro.
That said, manufacturers tend to design their Pro horns with better keywork, asthetics, and more adjustment mechanisms than their lesser horns. Some manufacturers will place better engineering and attention to the acoustic properties of their top horns. It all varies.
Student horns are typically designed with durability, mass produciblity, and intonation in mind. The idea is to create a reputable horn in as few manufacturing steps as possible, all the while leaving room for a player to realize it's limits as she/he progresses
Intermediate horns tend to vary a lot. I'm under the impression that some are little more than a student horn with laquered keys and a high F# haphazardly added to the design. Other horns that are considered 'intermediates' are identicle to their pro counterparts in key action and bore design, yet lack things like extra bracing on bell cups, ribbed construction, engraving, adjustment screws, etc. For instance, LeBlanc, the Yanagisawa distributor to the US, calls the 901 series an 'Intermediate' horn. I don't think Yanagisawa will admit to ever designing anything that it wouldn't consider a pro instrument and it seems Yani regards it's 900 series horns as Professional oriented (I would definitely agree with Yanagisawa here. There 900 series of saxophones are on par with any other proffestional instrument).
So there is no really cut and dry difference in every case. Just a few lose standards set up by internal marketing.