I though L2 + Square was the slow time one, and L2 + Triangle was heal.
Meh, I need to play through the trilogy again, I've been spending too much time on the Lost Frontier, that I've forgotten how the best work.
As for Daxter, it takes place just before Daxter rescues Jak in the beginning of Jak II, 'tis a good game, it expands on the Daxter segments that sometimes occur in Jak 3, and works well, as the focus on Daxter's gameplay means the PSP's limitations don't get in the way, unlike the Lost Frontier.
I'm tempted to do what Rayfist did in the Crash thread and note down my thoughts on each game, barring X, seeing as I've not played it much.