I like covers and bands who are playing them (well). For example, I didn't like
Dio at that time . I felt that his
Voice just put brakes to the riffs ((my apologize to Dio's fans, this is just my impression). Listening the recent compilation "A light in the dark" (tribute to Ronnie James
Dio), where bands such as
Metal Inquisitor,
Messenger,
Burden Of Grief, Iron
Fate and others are playing his legendary "The last in line", "Neon Knights" (
Burden Of Grief is amazing playing this song with its harsh vocal), etc., I finally love
Dio songs. I'm also not fan of
Deep Purple hard-rock, but I like so much "Solider of Fortune" played by
Black Majesty or "Smoke on the water" played by Metallium....and so on.
To conclude: In my opinion, playing covers are in the Spirit of Metal: provide consideration of the present bands to the predecessors and bring different stuffs on already made things as well.