[getsat]

And also a HUGE improvement in a lot of different areas! Speed, especially.

[meric]

I'd just never gotten around to it... Nothing I used (except Kod and new Smultron) really required 10.6.

[Stormbringer]

It is much buggier, frequent crashes of Safari, iTunes and Mail for instance

[sharednothing]

Not sure why you are getting down-voted. I have 2 MBPs. One is s ~3 year old running 10.5 and his baby sister running 10.6.

This is entirely subjective per my experience:

- the 10.5 'feels' more responsive.

- the beachball is a very frequent event in the 10.6, specially Safari, sometimes even when switching tabs which is quite annoying.

- I haven't rebooted the old MBP in months. Sitting pretty on my desk. The new one has frozen few times and occasionally I feel the need to put it out of its misery myself.