the one i have seems quite slow as it struggles to process quickly enough when i'm taking several shots in quick succession (which is apparently a must to get a single 'keeper' when photographing my kids...)
Anything decently fast will be okay, I tend to recommend Sandisk Extreme because they’re quick, but I use Toshiba Exceria Pro cards and have used fast Lexar’s in the past. For the file size on the X-T20 I’d be looking at a card that writes at a minimum of 150mb/sec if you’re trigger happy in RAW
fast sd card recommendations for my fuji xt20?
the one i have seems quite slow as it struggles to process quickly enough when i'm taking several shots in quick succession (which is apparently a must to get a single 'keeper' when photographing my kids...)