Had this very same discussion on PlanetWolfenstein forums.
My 2 cents worth…
Going out the Back Door has some advantages, but also carries great risk, and I think the risk outweighs the advantages. There’s no point building the Command Post unless you’re going to defend it, which will take 2 - 3 players or more, which will leave the Beach defense short-handed.
One man with an MG42 INSIDE the Back Door can hold it against Allied Cov-Ops getting in, leaving the rest of the team to defend the Beach.
The main argument for/against going out the Back Door rests on the assumption that Axis will lose a uniform anyway cos someone will either be stupid enough to go onto the Beach or will get blown onto it. I don’t agree with this assumption. Even on a public server, if the players are half-decent and know what they’re doing, there’s no reason why Allies should ever get an Axis uniform. If an Axis does get blown onto the Beach it’s not that difficult to prevent an Allied Cov-Ops getting his uniform (shoot the Cov-Ops!). As Allies tend not to survive for very long on the Beach it’s actually far, far easier for an Allied Cov-Ops to get a uniform off an Axis who’s gone out the Back Door.
Going out the Back Door doesn’t necessarily mean you will lose your uniform, but NOT going out the Back Door GUARANTEES you won’t.