To answer your questions directly...
ThreePM:what would make it work better from your point of view?
>>>As a consumer, I kinda feel there are lots of titles on stuff I don't know, and unlike at the newsagents, I'm not able to flick through to judge content. In addition, there's nothing else bar subscriptions on the site, so I should only be there if I'm intent to buy. It's not like I'm a farmer deciding to read a tractor website, and then figuring whilst there, I'll buy Tractors Monthly magazine or something. You're only there if you know what you're looking for, or know of key brands in advance, and just want a better deal. So I think all you need is good search engine optimisation, so when I decide in advance I want a subscription to title X, and type it into Google, I land at your site with the cheapest offer.
What's your feedback on its look and feel?
>>>The business one seems similar to the consumer one, but with more "blue" ^_^.
ease of use?
Headed straight to the A-Z complete list. A bit peeved I was then presented with alphabets, as if I could only view one letter at a time, but a quick go on the drop down menu just above the letters, and every title was listed from A-Z. I scrolled through, on the look out for titles I recognised, such as Drapers, or The Week. But dissappointed the mag I'm currently interested in subscribing to (Monocle) wasn't there, and left the site shortly after. Again, I think your visitors already know what they want. And if they're in business, they probably already get a lot of relevant business mags anyway. I wondered why I would want to subscribe to Architectural Record, if I already knew about Architects Journal. But was pleasantly surprised to see Computer Arts there, as I used to get that when it first came out.
I didn't check out the SME/Specialist, etc tabs, as I figured the A-Z list page had already showed me everything in one go. But I noticed the catagories were there, if I fancied clicking on them.
What features (as publishers) would you want to see?
References/testimonials from publishers to convince me you're worth talking to. Maybe some case studies, or more stats on results. Seeing you appearing in google searches for mag subscriptions, some attempt to lure a complimentary audience in? Something like a Facebook app, or MySpace page, I dunno...some form of active marketing. But then it's hard to ask for that, if you're not willing to pay for it.
What features (as customers) would you want to see?
The titles I'm interested in, at a good price, with clear delivery details. Example pages or scans for titles I'm not aware of, or at least, a link to the publisher's website, for me to clue myself up on 'em. The usual share on facebook / digg it / email a friend, etc, links below. So I can drop hints to friends what I want when my birthday comes up. ;-)