Assuming 'perfect' quality, there would be no difference. Both would be perfect.
Digital sound does sample. Hence 44.1KHz sampling rate - 44,100 samples per second, or 48KHz or 96KHz, etc. Analogue sound is theoretically at an infinite sample rate and therefore theoretically 'higher' in quality. The same is true of the bit depth (the number of steps available dynamically) - digital is stepped and analogue is theoretically not stepped.
they are very different. Digital sampling rates (particularly those above CD quality (44.1KHz at 16-Bit)) are so high that the ear cannot distinguish any practical difference between the recorded sound and 'natural' sound.
Analogue on the other hand does have a particular sound. Tapes are often driven hard and produce a slight compression, which is usually pleasing and helps 'glue' the low-end together on a track - the drums and bass can often fit better together than with purely digital recording.
For an analogue system to truly 'outperform' a modern digital system is terms of natural
sound, or rather accuracy
would be to all intents and purposes impossible. Digital sound is, by it's nature, clean and clinical. What goes in the A/D is what comes out of the D/A converters if no manipulation is applied (and by manipulation, I include downsampling and equipment besides the computer). Analogue sound is inherently transformed by the recording medium.
Furthermore, there are some really great emulators out there that can reproduce the sound of tape within a DAW. In one issue of 'Sound on Sound' magazine they actually conducted a blind experiment to see whether anyone in the studio could tell the difference between a recording done on a 24-track tape recorder (the specific model escapes me but it was essentially the best-regarded machine in the industry) and a modern DAW with software written to emulate the sound of that precise machine. The difference between the two was practically nothing and neither 'won' the contest.
If you want to record on tape, be my guest. I've done it. It's a lot of fun. Practically though, it's much harder to get good-sounding results on tape than it would be on a modern DAW system. There are specific difficulties with tape machines that make them more specialised - setting the azimuth, setting the bias correctly, choosing the type of tape and cleaning the heads. Also, you have to bear in mind that tape degrades so you cannot afford to 'run over' the same section again and again because it will compromise the quality of the recording.
Editing is incomparably more difficult on tape. Honestly? Unless you're very handy with a razorblade and have a lot of practice and time, I wouldn't even bother trying. Editing on a DAW system is quite literally hundreds of times easier.
Analogue (due to the limited track count) does force you to streamline your workflow and make mix decisions early. This is a good thing. It means you end up with a better result most of the time because you're eliminating the unnecessary cruft. Adapting the same technique with a digital system is a good idea if you have the discipline.
A lot of modern studios run a 'hybrid' system whereby they record to tape, dump the tape tracks to digital, edit digitally and then master to tape. That's the best of both Worlds really but still highly specialised.
In an ideal World, I would run the hybrid system. It's not an ideal World though and I don't have the patience to use tape regularly. I also don't want to be moving a 400-pound tape machine from one room to another when I could simply take my laptop. Or deal with the acres of outboard gear, or the setting up of the machine itself. Tape is a pain in the arse, although it does sound very good if you can get it right.
Here's a great article about the different steps that analogue systems use in recording:
It's very complicated. It's highly specialised. It's difficult and if I were home recording, I wouldn't be touching tape with a ten-foot barge pole. I would only consider doing it in a 'real' studio with 'real' money and a lot of time - and I have a good idea of what I'm doing.