I use Locale on my phone (similar functions, somewhat easier interface, share a lot of the same plugins). Had I started with Tasker, I would probably use it instead. I find it very useful on my phone, but haven't seen enough functionality to bother putting it on my tablet. Phone does things like change volume profile depending on my location and time of day, makes sure Bluetooth is turned on when I am in the car, sets which phones Google Voice rings depending on where I am and whether or not I have a BT headset connected, etc... None of which are of much use to me on the tablet.
I actually have a Tasker license and I keep thinking of switching because it does a lot more built in that Locale needs plugins for and that drives the overall cost up a lot, but I haven't been able to get past the more difficult UI compared to how easy Locale is to use to take the time to learn it yet.