The best thing about P1000 is it has 3G cell radio so you can use it as a phone. Hardware wise, it's like the first Galaxy S phones except P1000 has actual working GPS. I'm still running 2.3.3 Gingerbread on mine and have no plan to upgrade to ICS or JB. 2.3.3 stock Touchwiz European rom I'm running is rock solid. I have no need for buggy and battery draining ICS/JB port. But if you're interested in ICS/JB, I bet it runs pretty well similar to JB on Galaxy S.
But unless you plan on taking advantage of the 3G cell radio and use the phone feature, get the $200 Nexus 7.