The hot can actually disperses heat during use acting as a unintentional yet benficiary oil cooler. That is why some companies make heat sinks for spin ons to improve heat dissipation. Looking at the apogee of engines such as the v12 found in the Murcielago, you can see Lamborghini employs a spin-on filter. If its good enough for a 300,000 car, it must be good enough for our MBs. Also spin ons are no longer susceptible to sudden failure situations such as bursting, allowing higher oil pressures. In a spin on, the pressure is accomodated by the walls of the canister but in a spin there is more pressure on the insert.