I'm sure you'll be surprised to find out that microwave safe may not be so safe after all. There has been lots of news about BPA in the last couple of years. According to this article, BPA can leach from microwave safe containers after they are used. If you didn't have a reason to eliminate your plastic use for food then I think this should do it.
Glass is heavier and you have to handle it differently than plastic storage containers but it is worth it. There might be critics and studies that say that BPA is harmless or that plastics don't leach but why take the chance when you have a readily available alternative. The reality is that we need to evaluate our regulatory system and see if it is doing anything when it comes to product safety. We spend a lot of money on regulations and enforcement but we are continually finding products that are not as advertised.