Replaced half my row of Autumn Bliss with Joan J last winter, hoping to avoid raspberry replant disease which can happen if you plant in the same soil.
Only partially got away with it, and might have to dig out the strugglers, replace the soil, and plant a couple of spares I grew in fresh soil in their place.
Of the fruit I did get, as is claimed, they were about a third larger than the Autumn Bliss fruit, and definitely had a better flavour, at least as far as my taste buds are concerned.