Again it's a good lens but not an upgrade. The same IQ, same variable aperture and the extra 50mm will barely be noticeable (even nonexistent with focus breathing). And it's heavier and bulkier, so might be considered a downgrade in effect. The 70-300 is designed as a FF lens, the 55-250 (give or take) almost the direct crop equivalent which is more suitable IMO as it offers the same performance in a smaller, lighter package.
