Nexus 4 + Google Voice and Skype.

So I'm considering buying the Nexus 4 to lower my monthly cell phone bill. Right now, like most people, I'm paying in the neighborhood of $100/mo for unlimited text/internet/voice.

I'm looking to buy the Nexus 4, port my current number to Google Voice, sign up for unlimited voice with Skype for $3/mo, and sign up for the $30/mo unlimited text/internet/100 minutes plan through T-Mobile. Has anyone here used the $30/mo T-Mobile offering? What has been your experience with the service?

Here are a few questions and concerns I have about this:

- Will I have to use a different number for calls and text messages? IE: Calls from Skype can go through Google Voice, but how will I take advantage of the unlimited messages through the $30/mo plan? Or does Google Voice offer a free IP to SMS text messaging service as well?

- I went to a local T-Mobile dealer to discuss this with a representative and for one, she didn't sound like she knew what she was talking about, but she said something that concerned me. She said that the T-Mobile pre-paid plans use a slower internet connection than the T-Mobile post-paid plans. I probed further but she couldn't give any more details, so I'm unsure if she just wanted to sell me a plan through a scare tactic or she was remembering something from training. This is kind of a big deal, I want full access to 4g, whether that's LTE through another carrier or 42mbps HPSA+ I don't really care. Any insight on this would be wonderful.

- I read in the T-Mobile forums that the $30/mo pre-paid plan does not support call forwarding. Does Google Voice abolish this? Or is there no hope of using this plan with Google Voice?

So for $300 up front and potentially $33/mo I can have unlimited voice, internet, and text messaging. Is this too good to be true? If you see any caveats, or have any experience with a plan like this, please let me know!