I did my first LRFD analysis (Geotech) for some drilled piers for a bridge. It was a bit of a pain, but mostly because the method used here is very easy to determine bearing capacity with, and I had to update the calculations used after the first draft.
The soils at the location were sandy. The AASHTO code is very vague for these conditions – has you run through 5 different calculations, and then lets you pick a reduction factor based on the capacity your local practice would allow.
Unfortunately, I did not feel comfortable with a factor of 1 (thought it would be difficult to defend in court), so I feel the piers are over designed, based on local practice.
From a geotech point of view, I think the LRFD methods will be difficult due to the variability that we can see in the soils. On the structural side, I have seen things be easier or harder based on the situation.