I have used this with my PowerMac G4 AGP Graphics (Sawtooth)'s 250GB Seagate Barracuda 7200.10 since January 2007 when it's 120GB Samsung failed with no issues whatsoever, even when first using it. I did have to boot off it's secondary 80GB HD to partition my 250GB though as I had no bootable CDs with the ATA Hi-Cap driver installed. An external FireWire or USB device would have worked too.
My sister also uses this on her Gigabit Ethernet G4 and she has both 250GB and 500GB Seagate Barracuda 7200.10 and she has had no issues at all.
Because of the success of my efforts with this driver I am considering replacing my Sawtooth's 80GB with another Barracuda, preferably 500GB or larger.

And yes, I _have_ to brag, This is my Sawtooth in all it's glory (taken 4.4.07):
http://img259.imageshack.us/img259/1831/10022482md8.jpg

And here are the specs:
1Ghz 7455 (64k L1, 256k L2, 2MB L3), PowerMac G4 AGP Graphics (Sawtooth), 1.19GB RAM, Radeon 7000 64MB DDR PCI (183|234)/Rage 128 Pro 16MB AGP (225|137), 250GB 'cuda/80GB WDC, Matshita SR-8585F/Creative CD5233E, Mac OS 10.4.10/9.2.2
480w Demon Silver Chrome (ATX)/200w Mirage (AT)
ATX server case (6x 5.25"/3x 3.5")
17" DELL D1028L CRT @ 1600x1024/15" ACANA Pro 15Sp CRT @ 1280x1024
Technics SU-V6X amp (100w per chan)+60w car spks/Yamaha YST-M7

To recap, if you know what you are doing it is less than a snap to get this thing working flawlessly. The instructions were fine imo and it has never caused any issues. to this day my HDs and my sister's HDs remain problem free. (I do whole system diagnostics a minimum of once per month.)

This is a great ad blocker and yes it will work with Safari 1.3 under OS 10.3.9.
Don't worry about this crashing safari, from what I have seen only version 1.0 had a small crashing problem. I know because I was one of the people testing 1.0 and 1.1.

When I try to download I get a "550 failed to change directory" error.