3-2-1 cooks a bit faster in relation to pull-back and tenderness, and foiling does soften the bark quite a bit. I've used no-foil method for years, then tried variations of 3-2-1 and I liked the ease of getting very tender ribs. You can vary the times on open grate vs foiled to achieve tenderness ranging from bone-popping (overcooked, IMO, but many like 'em that way) to slightly firm but tender ribs with a light to heavy bark. More foiled time = more tender, more open grate @ the end = heavier bark.
If you want a relatively sticky rib with a moderate chew on the surface and medium tenderness, you might consider applying sauce immediately after removing from foil with a 3-1.5-1.5. For more tender interior, less exterior chew and less sticky sauce, 3-2-1 is a good starting point. The longer the sauce is on the ribs on open grates, the stickier it will get. With saucing, you will reduce/omit setting of the bark as well, and the earlier you sauce, the less time for the bark to set.
3-2-1 and variants give a wider variety of textures with your ribs. I have done 3-3-0 / 4-2-0 for tender to fall apart ribs with no bark, and 3-2.5-0.5 for tender rib with just enough bark to help it hold together...it just depends what you're after.
Straight open grate smoking will give a more firm texture and most developed bark, and the time your sauce is allowed to cook on the ribs will determine the overall moisture content of the sauce...more time = more sticky, less time = more wetness.
It's a coin-toss if you want to experiment a bit. No-foil is more of a purist form of hot smoking and carries a learning curve like anything else. It will yield a firmer interior with less shrinkage (due to lower average cooking chamber humidity, I suspect), but when done correctly, they can be very moist and relatively tender eating ribs. If you can play with chamber humidity, you can get a better finished product. Wet smoke (high humidity) provides the highest degree of smoke reaction, though if sustained, can cause a drier interior meat. If humidity is reduced mid-way through cooking, it can tighten the meat's surface fibers and create a barrier to reduce internal moisture evaporation. This also enhances the formation of bark, which can later be softened by elevated humidity at the end of cooking. Wet/dry/wet for smoke reaction, moisture retention and softer bark, wet/dry for smoke reaction with a well developed and very firm to crisp bark.
I hope that gives you a bit more insight as to how it all comes together. I'll be smoking a couple slabs of spares today in a vertical charcoal smoker (Brinkmann Gourmet), using the above method (wet to dry smoke chamber). Maybe I'll post the process and results later this evening so you can see how that works out...doesn't really help you with the saucing part of your rib cooking process, as I won't be saucing, but it may give you a few things to consider for future rib smokes regarding interior moisture retention.
Eric
