You want to steer away from Pertronix Ignitor 2.
That being said, P1 is a great solid upgrade, especially if you want a stock appearance under the hood.
What you gain:
1) Generally, you can run a higher voltage coil. Sure, you can do the same with points, only you'll burn them out faster if you do. Higher voltage coil = larger gapped plugs = more power = more efficiency. I ran the combination of P1 and 40kV Flamethrower from pertronix, and I gained about 3-5 MPG on the highway.
2) You don't have to worry about frying your ignition if you have the key in the run position but the car is not running. YOu may say, so what? Well, there are sometimes you have to work on electrical systems on the car that are tied to the Key On position, but you don't want to run the car while you are doing it.
3) You don't have to constantly adjust the points to get the best performance out of the car. To me, that was the main reason I switched.
All that said, I think DS2 is a better upgrade overall as you can run thicker wires along with a larger cap that can help reduce crossover firing (generally only a concern on racing cars at high RPM). DS2 is also an over the counter upgrade where you can get all replacement parts from a normal discount auto store so if something goes wrong, you aren't stuck waiting for the mailman.
But, for stock appearance, Pertronix is a great upgrade and one I highly recommend. I've run both set ups and here is my feedback:
http://www.kastang.net/pertvds2.html
Slade