Ramifications of Reinstalling from a "Fresh Image"

[Software Monkey]

In the Tips & Tricks forum post "How To Keep Your System In Good Order", it recommends:

If you haven't  updated your system within the past 30 days then download a fresh ISO and install from the updated CD.

Which raises a couple of questions in my mind.

First, does the reinstall wipe the system disk, or can it be done in such a way as to retain your existing configuration (my '/home' is on a separate disk).  That is, will I then have to set up system-wide configuration and additional software packages all over again and go through the pain of recreating users and groups and resetting permissions and ownership for my user's home folders?  If so, that's a serious deterrent.

Second, given that the current download of Full Monty is from Sep 2011, and it's now Feb 2012, it's simply not possible for a new user to avoid updating from more than 30 days ago (in fact it would be about 150 days and counting).  I just installed from that ISO and did about a GiB's worth of updates (900 and something MiB), without problems.  Is this advice from 2008 now obsolete?

From my past experience, I usually do updates about every 1 to 2 months, and I want to be clear on whether the advice given is sound.

[Old-Polack]

Software Monkey:

Our upgrades can come at any time. Sometimes there may be a week or two without any new packages, other times packages are upgraded almost continuously, for days on end. I have update-notifier installed, and set to check for upgrades every 8 hours. Whenever it signals new upgrades available, I upgrade. Sometimes that's 3 time in one day, but it keeps the individual upgrades rather small, compared to letting them stack up for weeks at a time.

Odds are you can still upgrade successfully, so give it a try. The worst that can happen is that you do need to reinstall. If you wait, you may cross that threshold where you can't do tomorrow what you still can do today.

[Software Monkey]

Software Monkey:
I have update-notifier installed, and set to check for upgrades every 8 hours.

Thanks - found and installed that; however, in our case it's primarily the kids using the box, so it will be likely be several weeks between each time I am on it. The beauty of Linux has always been that ultra low-maintenance required compared to Windows.