I've always had and used Sandisk. In all cameras (dslr) and hd camcorder, as well as my go pro now. But as with my original SP1, it just doesn't play nicely with sandisk.
My best advice. Get a Samsung pro micro sd. I just did two days ago. Went to best buy, they had 64gb on sale for 79.99, but price matched
amazon for 39.99. its 90mbps read 80mbps write. Now that's all *up to* speed claims. But so far, happy with the Samsung.
Before the Samsung, I went pny route. Not that they ever gave me any problems, but I just don't feel comfortable with pny. I've gone through several of their 128/256 usb 3.0 flash drives now, and none have withstood over a few months of 'some pretty good usage'.