My review of Mac OS X Lion for Discovery News represented a departure from long-standing practice: For the first time in maybe a decade, I reviewed a new Apple operating-system upgrade by installing it on my primary computer, not an expendable review machine.

As you can read in that writeup, the installation went fine on my late-2009 iMac, and I consider Lion to be a good deal overall. But I also disliked enough of Apple’s changes to prior Mac behavior that I found myself quickly undoing these new defaults–which is another thing I traditionally haven’t had to do with a Mac upgrade. Here are my major corrections:

Tame scrolling and zooming behavior. By default, Lion imposes two iOS aspects on OS X, “reverse scroll” and “smart zoom.” The former has you flicking two fingers in the direction of scroll on a Mac laptop’s trackpad or a Mac desktop’s Magic Mouse, as if either were the screen of an iPad or iPhone–i.e., the opposite of how you’ve scrolled on a computer until now. The latter zooms into a window if you tap two fingers on either input device–which I found myself doing unintentionally way too often. Fundamentally, I think you need a different user-interface grammar on a computer and a touchscreen mobile device. As long as the computer requires you control it through indirect manipulation–that is, by touching something besides the display–the mobile model breaks down. If you agree, you can undo both of Apple’s changes in the Mouse and Trackpad panes of System Preferences.

Show scroll bars. In general, I appreciate Apple’s willingness to edit out complexity and pare things down to the minimum. But hiding scrolls bars until you start to scroll with the mouse or trackpad seems an enormous mistake. In long documents, I felt lost and kept gesturing with the mouse to force the scroll bar to resurface. The effect was even more annoying in Web forms on a page and in other cramped, scrolling-required boxes. And to what benefit–to save a few pixels of screen real estate on the right edge of the window or form? No thanks, Apple. I’ll live with that clutter if it stops me from reflexively twitching a finger on the mouse every few minutes. To undo that mistake, click the button next to “Always” under “Show scroll bars” in the General pane of System Preferences.

Make the Library folder visible again. Apple somehow elected to copy one of Microsoft’s stupider interface decisions by hiding the Library folder in Lion. This is where your applications store their preferences, supporting files and some of their data–and it’s far more human-readable than the tangled array of hidden “AppData” sub-folders in Windows 7 that Microsoft hides from its users. Many common troubleshooting routines require access to your Library’s contents, but Lion hides the entire folder from view. To make it visible again, open the Terminal app and paste in the following command, then hit Enter:

chflags nohidden ~/Library

(That comes from a TidBITS post, but there are other ways to get at this folder. Macworld offers a full 18 workarounds.)

I may adjust more of Lion’s defaults as I get more familiar with this operating-system upgrade. I can also think of other changes I’d make on a laptop–for instance, setting Lion to show a messages when then screen is locked, then maybe adding Boxee to replace the Front Row media-browsing software Apple excised from OS X. But for now, these are the big three fixes I’d make to any Lion installation. What’s on your own list?

Update, 9/7, 4:17 p.m. Since writing this, I’ve had to change two other system settings:

• To stop getting flicked from the Finder into the Dashboard by an unintended two-finger gesture, I unchecked the “Show Dashboard as a space” checkbox in System Preferences’ Mission Control pane.
• After twice losing work when my attempt to scroll horizontally led Safari to assume I wanted to go to the previous page–after which this browser failed to return me to the blog post I’d been composing–I unchecked the “Swipe between pages” checkbox under the “More Gestures” heading in System Prefs’ Mouse pane.