If you don't mind some assembly required, you can go with the Slow Stick and have more flexibility selecting your radio system (receiver, servos, etc.) and customizing your power system. The Slo-V is almost the same plane but with a V-tail. The big difference is everything is included in the box and it's ready to charge and fly.

You'll pay more for the privelage of assembling the Slow Stick, but the high quality batteries, radio system, and charger equipment you buy for it can be used for many electric planes yet to come. The bundled radio, flight battery, and charging gear that comes with the Slo-V works fine, but isn't really "hobby quality" equipment.

Both are very good choices, it's really just a matter of whether you want to spend more to build but end up with higher quality electronics, or if you just want a good plane you can get up in the air quickly. With the Slo-V now priced at $99.99, it would be awfully tempting for me to take the shortcut.