Thanks for the encouraging note, Graham.
Nevertheless, it seems that, in this case, R&D has gone backwards (which is worse than standing still whilst claiming to move forward--see below).
Granted, platform and OS revisions must be an ongoing headache for your development team at the best of times, and I remember updating from QXP 6.1 to 6.5 under Mac OSX10.3.9, only to find that OpenType (OT) fonts that ran happily under 6.1 produced PostScript errors when printing from 6.5; so we downgraded back to 6.1 and have been there ever since.
And I'm still also using a very modest setup myself (PowerMac G4 dual 1GHz with 1.5GB RAM and a couple of 36GB internal SCSI drives running OSX10.3.9) which has been steaming along for years with QXP 6.1 running impeccably. In fact, so trouble-free is this combination that I wouldn't even consider a new all-singing Mac before satisfying myself that the required QXP 8 (and everything else) are up to the task themselves. With this in mind I decided to step up to OSX 10.4, and here's what I found: QXP 6.1 still runs, but no longer displays OpenType fonts accurately on screen (characters actually appear outside of the text boxes at certain magnifications, which makes on-screen editing a nightmare). QXP 6.5 is the same, but I guess these were never certified OT compliant. However, Quark 7 claimed to fully address OpenType font issues, so I downloaded the test drive---surprisingly, the OT display problems still persist even in QXP 7. So I bit the bullet once again and upgraded to QXP 8, and that problem has at last been fixed.
But back to topic, it seems that the on-screen display of imported EPS files has really gone backwards. Yes, the full resolution preview option under QXP 6.1 used a stack of memory and would occasionally hang the app. But the irony is that even with full resolution preview switched ON in QXP 8, the on-screen display of EPS files is still inferior (e.g. fuzzy text) to that in QXP 6.1; whilst any text in imported EPS files displays pin sharp in QXP 6.1 even with full res. preview OFF; that knocks the socks off QXP 8! And there's nothing more painful than not being able to see clearly what you're doing. (Note: if you're still listening, perhaps we can also have an option to turn off the new picture bounding boxes with those hideoous blobs all around the edges--these are a major on-screen distraction to say the least!)
As Zikan said, there's a quality here in QXP 6.1 that seems to have been removed in QXP 8, which is surely a backward step.
I'd like to see Quark regain its market share and kick ID into touch, not least because we're 20 years up the QXP learning curve, so by now QuarkXPress is part of who we are, plus we need to access an archive of Quark-generated publications going back just as long. But progress with QXP seems still to be painfully slow, with basic features that used to work well now becoming broken (another e.g.: after very nearly two years on the market QXP 8 still generates PostScript errors when trying to output master pages), hence we are, for the first time, reluctantly bothering ourselves to evaluate the competition--and thus far I regret to say it's looking very good indeed.
With that in mind, it is of great relief to hear that you are indeed 'paying attention', because QuarkXPress 8 still really needs to kick some ass.
Meanwhile, my QXP workstation back to 6.1 where I can at least churn out some work. If it ain't broke, don't fix it, as they say.