Nexus 4 on Straight Talk

I know the Mobile forum is perhaps more appropriate for this topic, but this forum is actually active and you all are my brethren.

I'm currently carrying two phones around with me: My LTE Galaxy Nexus (Verizon) and my Nexus 4, which I have running on the T-Mobile prepaid plan. I've been happy with it, and I'm likely going to port my VZW number to it before the next billing cycle. But I was also considering using StraightTalk to save some more money.

But I had a couple of questions.

  1. I've heard of users of StraightTalk being pretty aggressively throttled. ~200mb/daily usage caps, and service being outright shutoff at 2gb. However, I've also heard this mostly of their service via AT&T. Do the same limitations generally hold true when used with a T-Mobile based SIM on StraightTalk?
  2. Being that virtually no prepaid carrier supports voicemail forwarding (for use with Google Voice), I've been using T-Mobile's Visual Voicemail app, which actually isn't half bad once you block the ads. Does this app still work with a T-Mobile/StraightTalk SIM? I'm not keen on porting my number to GVoice, because I use MMS a lot, and I don't like the way it handles SMS.
Thanks!