Bad value still. At the very least, M&M miles are worth 1 cpm when redeeming for long-haul C and F. Often, you can get a value higher than 2 cpm.

Note that if you don't have sufficient miles for a long-haul premium cabin redemption, perhaps the new mileage pooling might be an option. Or redeeming from a different program. With BAEC, for example, short-haul awards out of LON can be decent value.