Be prepared for the two main issues:
1) Huge amounts of theory covering all sorts of stuff you never knew you needed to know [because you don't].
2) Lots of flying using an ADF needle, in particular holding patterns
and, less problematic
3) a bit more procedures using DME-based navigation; markers are rare
4) much fewer GPS approaches
5) a quite formulaic, predictable test format with no oral exam [you could see that as a plus]
Actually flying IFR has its own challenges (CFMU / flight planning, problems routing at lower levels)