I havent been RIM's biggest Playbook fan and even with their 2.0 OS upgrade, it feels unfinished and rough to use. I wanted to see how the Playbook would perform compared to a Windows 7 laptop when using WIFI sharing of my iPhone's 3G connection.
I closed all the apps on my iPhone 4s, did a force shutdown and restard. I placed my phone 4 inches away from my Wilson cell phone booster and it had a full 5 bars.
I then started the Personal Hotspot function on the iPhone and connected only the Playbook. I ran the Speedtest.net test twice and received similar results.
I then turned WIFI on the Playbook off, placed the laptop in the same location and performed the same test
Notice that both tests where conducted using the same test server.
when I performed the test via the Speedtest.net iphone app, the results were very close to those from the laptop.
This is far from a scientific test but it confirmed my "feeling" that the Playbook was slower than the iphone or laptop when using 3G WIFI Sharing.