I use Quark everyday at work and I use InDesign at home. InDesign is a far superior program. Among the features that I like are: built-in Preflight, full PDF export functionality (Quarks PDF Export is absoutely terrible), transparency, and the prize winner...If your computer bombs or the power goes out or whatever and you open InDesign again it will be exactly where you left it. No other application that I know of does that and I wish Adobe would roll that feature into their other apps (and with the amount of times Quark crashes they should have this feature).
On the other side, Quark's validation process for upgrades and installs is terrible! You have to go to their Web site, input multiple times these really long serial numbers for both the new and old versions (all on a site with little to no instructions) then they give you another long number which you input into the program. And then you have to go through the registering and activatation. Adobe's activation is all automatic. If you are simply upgrading, it does everything for you.
Quark had a monopoly for many years and therefore had no innovation (look how long it took them to get to OS X). Now that they have competition, they are finally starting to pull their act together. Quark 7 actually looks like it might be a decent program (because they have taken many of the things that InDesign does and added them to Quark). Quark 6 has added maybe three or four major new features since version 4, most of which are useless (who wants to edit images in a page-layout application or use Quark to make Web pages?).
