I tried both configurations and I like closed back a lot more.
When I bought my Stiletto 2x12'' cab along with the LSC head, since I had always used open back amps before, I built myself an open back panel to replace the closed one on the cab. I played it for a few times (a couple of months more or less) and it wasn't bad, but when I switched back to the closed back configuration I ended up liking it much more: to my ears the sound is more "compact", powerful and balanced especially on the dirt side but I like it more even on the clean/crunchy tones.
Hope this helps! :wink: