Well, I finally did it. I moved my number out of Google Voice and got a normal cell phone plan, and I couldn't be happier (well except that my monthly bill will go from $30 to $50). I ported my number to Google Voice 18 months ago to use my iPad mini as a phone with just a tablet data plan. I eventually got another phone, the Android Nexus 5, but I kept using Google Voice with a tablet data plan because I really got accustomed to making and receiving calls and texts over wifi on my smartphone, tablet, and laptop. This was especially handy in areas with bad cell reception. And you couldn't beat the price: I varied between tablet data plans that cost $9-$30 per month.
However, I eventually got fed up with Google's lack of attention and commitment to the product. They killed 3rd party support without replacing any of the features 3rd parties had built on Android, even though they had integrated these features into the Hangouts app for iOS. This meant I could no longer make calls from my number on Android, even though I could on my iPad and laptop. There were rumors that Voice would be integrated into Hangouts with a suite of new features and it would be announced at Google I/O in June, their developer conference. However, the conference came and went without a peep. In the end, I got sick of waiting for Google to fix Voice's most glaring hole: it doesn't support MMS (aka picture messages). I was tired of missing pictures friends sent me or group messages that were sent as an MMS. I'd been waiting patiently for a roadmap to seeing it fixed, but apparently it's not coming any time soon.
So I ported my number to Straight Talk, one of the best prepaid smartphone plans available. At the same time I found a good deal on a used iPhone and decided to quit waiting for the iPhone 6. The initial port took a few days to go through and at one point I was getting calls on my new Straight Talk SIM, but still getting texts through Google Voice. It took a few more days for MMS to start working, but once it did I randomly got a picture message from one friend and a group message from another. I wonder how many I missed over the last year and a half.
I do miss being able to call and text from my laptop or iPad over wifi, especially because I don't have the best cell coverage in my house, but at least I can iMessage and FaceTime. So when the whole process was finished I went back and signed up for another Google Voice number just in case I need it in the future.