Differences between SMB and the muti-game cartriges?

Has anybody ever checked whether there are differences between the standalone version of "Super Mario Bros." (NTSC) and the version that appears on official multi-cartridges like "Super Mario Bros. & Duck Hunt"?

After all, it cannot be the exact same ROM image, can it? At least all the addresses should be different.
But are there any gameplay changes?
And can you exploit certain glitches and bugs with one version that you cannot do with the other simply because the addresses are different and unintended behavior will express itself differently on both versions?

Not necessarily. If a 32KB bankswitching scheme is used, I don't see why everything couldn't remain at the exact same addresses. A small reset stub might need to be included, but that wouldn't affect the rest of the PRG-ROM in any way.

Super Mario Bros + Duck Hunt has an identical copy of Super Mario Bros in every way, except for 8 bytes changed at the beginning of the rom.

I vaguely remember a game compilation for the Genesis (which has a larger address space than the NES, so the games were in fact relocated) where Sonic 1 ended up with a few glitches (palette-related I think) because of address changes.

The Famicom Disk System version of Super Mario Bros. is not identical to the cartridge version, although to the end user it will play identically. How could it be when the FDS shifts the memory space used by the PRG-ROM to 6000-DFFF? Perhaps as a result of the porting, the Minus World is noticeably different and can be completed.