Storm, an inter-service transfer is extremely difficult to get, and you have to pay back any bonus you get from your original service, as well as lose your contribution to the MGIB.
As far as comparison goes, the Marine Corp is tougher in it's initial phases, plus it is harder to make rank and stay in. The Army is easier initially, and to make rank in, and has more options. Ultimately, Your DD 214 is the same, either way, and doesn't make a difference which branch you served in after you get out. An individual employer might be impressed, but overall it makes no difference. You are able to get your job guaranteed in the Army, most marines can't get that. If you are interested in Airborne Ranger, you want to enlist for infantry with a Ranger guarantee in your contract, and possibly Sapper school as well. Sapper school will help if you want to go SF. If not, it actually is impressive to have both tabs on your shoulder. Oh, there's also more reenlistment money for the Army right now.