'A 'painfully slow' Intel Mac probably needs the hard drive replaced (which would be warranty)' - is only an assertation. The capacity, speed, and overall performance of the hard disk drive, hdd, here and with others is acceptable and not related to the Mac Minis performance (non video editing). As for installing a larger capacity hdd -
BestBuy has a 120 GB for $199.00 (impressive).
The problem of the Mac Mini's sluggishness is due to insuffienct RAM. Not that 512 MB is insufficient. MacOS X'es hording and allocation of the 512 MB causes the sluggishness. And yes, applications such as 'Finder' and 'Safari' add to the overall sluggishness (because of excessive threads and / or memory leaks). Using 'Firefox' on a stock 512 MB Mac Mini works fine.
-----
LJH -
If you intend to purchase a non custom built Mac Mini - consider the purchasing of a minimum of 1 GB of RAM.
The Mac Mini currently comes with two (2) 256 MB memory cards, mc. If you do purchase at a minimum 1 GB - purchase a single 1 GB mc - not two (2) 512 MB mcs. This will allow you, in the future, to increase the RAM size to 2 GB.
If you believe the 60 or 80 GB hdd is too small in capacity, then consider purchasing a larger hdd and install it at the same time you install the RAM.
To crack open a Mac Mini and perform a RAM and / or hdd replacement see this '(
OWC)' video (as one of many sources).
-----
I was about to purchase a PPC based Mac Mini when the Intel version was announced. I then decided to wait a little. Just recently I was handed one. Now I am in the process of purchasing 2 GB of RAM for it. I do recommend it to many - as long as they know to purchase it with 1 or 2 GB of RAM (however, Apple is typically more expensive), or are prepared to install 1 or 2 GB of RAM - unless they will only be launching one or two applications.