Hi there.
In my recent song "Great Sky", I did two versions - one with my usual programmed drums, and another with live drums (performed by a real live drummer!).
Version with programmed drums is
here, alternate version with live drums is
here.
A few interesting things I noticed:
Obviously, with programmed drums, I start from scratch - I program the rhythm and the groove beat by beat, bar by bar. It can be tedious work, and it's not easy to get realistic or appropriate results. On the other hand, I've had some practice over the years and developed some skill in drum programming. This doesn't mean it's any less tedious, but I'm getting better at achieving the results I'm after.
Using a live drummer, I'm no longer in full control of the rhythm and groove - the drummer provides it. With a good drummer, this doesn't have to be a bad thing. A good musician will understand the intention of the music and contribute to that in their way. Unfortunately I'm something of a control freak, and I've usually got quite specific ideas about what I want in my music. I could edit the drum performance (and I did a little in Great Sky), but taken to extreme I could easily rewrite the performance completely. At that point, I may as well sample the drum kit and program it myself!
There's also the time factor. Programming takes more time for me than recording a drummer - but the difference might not be so great once you factor in the drummer's time too. From my perspective, using a live drummer is a trade-off to save time at the expense of control. In this respect, using a drummer is not very different to using loops. The drummer also brings their perspective to the music and adds "another cook to the broth".
Sound is another factor. With programmed drums, sound is fairly easy. I have umpteen different kits to choose from, and I can audition different kits and combinations by simply clicking my mouse. Each kit component has its own mixer channel, and I can have exactly as much bleed and room as I want. I'm grateful the hard work of recording the drums has been done for me.
Live drums are an entirely other story. On my budget, I'm limited to the kit the drummer has - I'm not running projects where I can hire twenty kits just to try them out. Likewise, I'm limited to using a handful of microphones in a less-than ideal room. The result is that it's significantly more difficult to get a good sound, let alone the sound I'm going for with the song. In the mix, it's just as hard to control the sound. In Great Sky, we recorded the kit with four microphones - kick, snare, and two overheads. To change the balance of the kit, I had to resort to tricks with EQ and compression, where I would simply have pulled a fader on a sampled kit.
It was a good experiment, but at this stage I'm probably going to stick with sampled, programmed drums. Better control over the rhythm, groove, and sound do it for me.
-Kim.