Well if your friend just switched from using OS 9 to OS X of course he would call it slow. OS X takes some getting used to but when users realize that they do not have to make tea while they burn a CD for example they find it hard to go back to one-task-at-a-time OS 9. Basically your friend lives in the past.
It seems there's a really naive breed of mac zeliot rearing it's cluelessly devoted head since OS X came out!!!
OS X is not perfect, someone wanting to stay with OS 9 is NOT living in the past, they're living in the realworld, a world where they're software does what it's supposed to do and they can actually use their software in the first place, they also might not have a spare 3 grand (underexagerated) to pay for plug-in upgrades and/or replacing their whole system due to the fact any mac with PCI graphics is worthless for protools under OS X!!!
I know Protools 6.0 has far smoother screen redraws and the interface is snappier under a high load under OS X on a dual G4 , lots of people have commented on this and from a technical point of view, this is purely because Protools 6.0 is fully multi-threaded and can use 99% of 1 cpu purely for plug-ins leaving the other cpu to handle MIDI, automation, screen-redraws etc... The OS 9 version just uses 85% of 1 CPU for everything. Apart from this, Protools 6.0 (and subsequent bug fix releases) are causing a LOT of people problems.
On top of the 100s of problems people have been having, a lot of people have seen pathetic increases in processing power with the new mac models. the difference between OS X and OS 9 performance has only been in favour of OS X when dual cpus are used and even then, people running a lot of OS 9 only software synths and plug-ins just CAN'T use OS X at present for lack of software. Running Protools 6.0 on a single cpu G4 seems to be hell for a lot of people, lower plug-in counts, sluggish performance, OS X really does seem like the bloatware OS from hell unless you've got loads of cpu power to throw at it.
To give you some example of exactly how OS X performs with Protools LE, here's some random results from a benchmark test members of the DUC have performed called the "dave c test" :
Dual 500Mhz G4 19 tracks (11 under OS 9) - This is very impressive but exposes the huge weakness of the G4 when far higher clockspeeds don't even come close to double the performance.
Dual 1.25Ghz G4 29 tracks, Dual 1.42Ghz G4 32 tracks (not OS 9 bootable)
Single 1.2GHz G4 24 tracks (Sawtooth G4 '100Mhz FSB' with a sonnet cpu upgrade)
If it wasn't disappointing enough to compare single vs dual cpu performance (you're not getting you're money's worth of out of a dual 1.42GHz G4 at all), it completely takes the piss once you compare it with PC results like this :
2.24Ghz Pentium 4 : 32 tracks + 24 aux (taken from the 'best system for under $1000' thread in the PC protools LE forum)
That's 160 plug-ins on the most expensive mac or 280 on a PC you could build in triplicate for the cost of the Mac. It's not digidesign's programming that's causing such a wide performance gap, it's bandwidth restrictions of the G4. I shudder to think how a 3Ghz Pentium 4 would stack up against the top of range powermac but a 2.8Ghz Pentium 4 of similar spec to the 2.24Ghz model didn't even manange 1 extra track so maybe it's not so bad.
It's almost entirely Apple's fault this situation even exists, if they hadn't dropped OS 9 support, digidesign would have had more time to work on Protools 6.0. and get all the bugs out, as it stands, without releasing it even in it's present form, they would be denying the whole audio community the industry standard system on the industry standard platform.
If you're looking for a multi-track sample editor and you've got a mac that can boot OS 9, get protools free just to try it out. The only thing that might throw you at first is that you need to create 2 mono tracks to record in stereo, this is because it's based on a fairly old version of Protools LE. For quick, basic 2 track editing, Yamaha TWE 2.0 is rock solid and free (if they have a place to download it still, it's fairly old now).