Unless you intend to participate in dick swinging contest, 1.25GHz will be fine.
As a 1.5GHz model owner, I can say that even if you win the "dick swinging contest", you get your dick burnt: part of me regrets prioritizing bringing it with me to my new home instead of the 1.42GHz model I used to have (or technically
might still have, if it wasn't stolen) for simply a few small-ish reasons:
- It works slightly better with the Mac OS 9 port for the Mac mini G4 in terms of misc. hardware compatibility (i.e. monitors, resolutions etc., probably also the cause behind issues I had with a PATA SSD from brand "Super Talent"). Thanks to this, I use my DELL monitor at 4:3 aspect ratio (with black stripes on the sides), instead of using its full 16:10 aspect ratio screen as I could with my 1.42GHz model;
- Many settings saved to NVRAM/PRAM do not persist on my machine (many others do, though, such as date and time). For instance, the "Startup Disk" control panel cannot
actually change what is my default partition to boot from (at least not when used in conjuction with the rest of my hardware), and if I want to change the default, I have to hardcode it straight from Open Firmware a very, very long string that I obtain by using the little-known "
System Disk" utility. Gotta do this each time I switched partitions: this was COMPLETELY unnecessary using a 1.42GHz model with the exact same SSD model, size and IDE-to-mSATA converter (MARVELL-based);
- Related to the previous point, I also cannot create RAM disks anymore, the setting just won't get saved, since you need to reboot when you turn it on, but upon rebooting, the setting is undone. My workaround for that is to use a program called "
Make RAM Disk" (much better than i.e. "
ramBunctious"), but Apple's RAM disk feature is still slightly missed, because of the ability to save, and load, the contents automatically after shutting down and booting up again;
- Also related to the NVRAM/PRAM issue, some of my settings from the Keyboard control panel do not get saved, and I find myself reapplying them
each time I boot up. To remediate this, I added an alias (shortcut) to the control panel to the "Startup Items" folder in the System Folder.
Did I reap benefits for the extra VRAM (32 MB vs. 64 MB)? In practice,
NO. And the benefits of the extra 0.08GHz CPU clock speed?
Hardly, in practice you won't really feel much. Compressing/decompressing does improve proportionately, but that's barely much of a difference for one to really care.
Especially if it means running into the problems I described above.
Oh, and make no mistake, the 1.25GHz model is
100% marvelous and delicious with OS 9, too, I also used that. In terms of noise, even my 1.5GHz version is really damn silent, BUT, IIRC the 1.25GHz did indeed have that ever-so-slightly edge that gave me the impression it was turned off even when it was on. The speed decrease of 0.25GHz is something, but not all that significant, and completely unnoticeable when you are not compressing/decompressing.
However, I
do think the 1.33GHz "silent upgrade" model can be deemed a "trap": it supposedly shares the SAME New World ROM revisions that are seen with the 1.5GHz model, meaning all the issues I mentioned I have are
bound to also be 100% applicable to that model as well, but without any of the benefits: it is slower than even the 1.42GHz model, is still limited to "just" 32 MB of VRAM like most of its siblings AND may have those issues I described. I never sought that model, but I would not bet on it.
TL;DR Go for the 1.25 or 1.42 GHz models if you can, they are better unless if the Mac heroes that brought Mac OS 9 to the mini come back to address a bunch of issues (don't bet on that happening, they did enough for us, and I don't imagine they will be inspired to fix these). But if all you can get are the other 2 models (1.5 or 1.33 GHz), then that is fine as well, but expect further caveats.
