I used to play in standard tuning all the time, because I hated the thought of having to retune and I like being able to play
slide and fret, even alternating between the two, on one guitar. I have just recently learned playing in Open E, which I thought at first would be limiting, because you can't easily play minor chords. But I found a way around the it by dampening the 8th note or fretting behind the slide.