Replaced a set of Gibson 61 Burstbuckers pickups in a Les Paul Classic with Lollar Imperials. The difference in tone was night and day. Lovely blues tone right up to hard rock and could be pushed further if needed. Nice punch and growl from the bridge pick and an almost single coil qualities on the neck, very versatile.
In comparison to the Burstbuckers the tone was for more workable overall, slightly lower output level which I always found to be too high and very harsh on the bridge in the BB's but also too muddy on the BB Neck PuP.