Gradients....
First we had font rendering (Mac OS native font rendering and smoothing is a lot better looking than Photoshop at any setting. So is the Freetype library (used in a lot fo Linux SW) for that matter.
Then Image scaling... Doesn't matter what version of Photoshop you use nor which settings you use (including the new next-to-useless Bicubic smoother and sharper). Image scaling just PALES in comparison to what's built into Mac OS X by default. It pales in comparison to what came with a bunch of Amiga graphics programs back in the early 90's. Scaling things like icons down to smaller sizes generally produces results that are simply not acceptable. Scaling with the OS is a much better starting point.
And don't get me started on how Photoshop still can't stroke circles to save its life. You're pretty much better off doing any type of shape creation in Illustrator and then pasting the results into Photoshop (using Photoshop's own vector shape tools are not a solution).
So now the latest... Gradients. You'd think that setting up a simple linear gradient from black to white over a span of 256 pixels would produce 256 lines each of a different shade (you know, 8 bits of color and all that). You'd be wrong. Each time you create the gradient you get something different. Every time it skips shades however. Like going from 89 directly to 91 or 103 to 105. Next time it will skip from 90 to 92 and perhaps 107 to 109 (instead of the previous two). It's bad enough that when working with transparency Photoshop's settings allow only for single-digit percentage values (that's only 100 possible values, even though I'm using an 8-bit alpha channel). But then when I want to quickly make a plain gradient myself to generate a custom channel, it can't even handle that.
This is all fundamental stuff. Forget the fact that every Adobe app has a different interface and are generally very incompatible with each other (opening and saving files excluded), or that key usability features are added to one program and then excluded from all others (finally being able to change the font size of the interface in Photoshop after umpteen years - but not any other Adobe app).
Now they've bought Macromedia... So when the next Creative Suite comes out all current Macromedia products will likely be EOL. So much for any competition at all. Seriously, Adobe's software makes Microsoft's look like the most polished and bug-free in the world. And all that "goodness" with fairly long product cycles for practically no innovation between versions (hell, I'd say practically no innovation between 3 or 4 or 5 versions - excluding the jump/bump when InDesign was first introduced).
Sorry for the rant, but spending this kind of money would normally be plain stupid. In this case it's just a given because there's simply nothing else out there. And Adobe have known that for a long time. Too long.
Bruno