It turned out really well! Things I learnt:
Use the two Weber baskets, one on each side of the chicken
Ensure that the chicken is very securely skewered to the spit. As it cooks its shrinks and it came loose on my spit half way through
Have the temperature high, 350f to 400f, to get a crispier skin
Briquettes may work better than lumpwood due to longer, steadier burn
I haven't tried anything else yet, but I really want to try to do a homemade doner kebab on it.
I think Pichanha would be awesome! Let me know if you try it.
Honestly I have no idea about the smokey mountain question. I think that so long as the temp is high enough it should be the same principal. The main reason to use the rotisserie is to get the chicken to baste itself in its own juices as it turns. I don't think you would need to be close to the coals so long as you can get the temperature around the chicken high enough.
Hope this helps!