Solid little multitool
This tool has everything you need to make any adjustments or fixes on the trail EXCEPT a chain tool, so make sure you or someone brings one of those out with you too. That being said, I throw this tool in my pocket or bag on every ride I go on. You never know when your saddle or headset will loosen up, and this tool is perfect for the job.
The Park IB-2's design offers a comfortable grip and solid feel. Although an chain tool would make it the ultimate "everything I need, nothing I don't" multitool, I think it would take away from it's feel in your hand and it might make it feel awkward or bulky.
The IB-2 doesn't include a Phillips head, but I have been able to make due with the flat-head instead. All of the adjustment screws on my drivetrain are both Phillips and slotted, so not an issue for me.
I also have a Topeak Alien, and while that tool has everything you could ever need, it is big, heavy, and very uncomfortable to use when you're trying to torque something like a crank bolt (real tight). This tool has a much better feel in my hand and lets me get torque bolts without a problem.