Quoted from someoneelse:

The correct (!!!) felt protectors to exactly the same - they hold the legs about 2-3mm away from the cab. The most important thing is to not let the legs edges touch the cab/decals. I've actually seen setups in which the Stern style protectors couldn't keep the legs completely off the cab, guess that depends on production tolerance of the legs themselves. This never happens with the felt ones as they are much thicker than the metal ones.
The "normal" felt protectors actually don't really protect as they're usually to thin, to soft and to big so they sit in between the leg edges and the decals. The big plastic things also don't protect at all, by the way, they are made to cover up existing damage, not to prevent new damage.