Natit
I found the CIR course to be some of the hardest flying I have ever done. Most of the CIR students who I have spoken to have agreed on that.
The C182 is used for the first 2 nav exercises and an hours flight over the top at PMQ doing ADF work. You then get to move onto the Baron doing, I think from memory and without my logbook at hand, about 2.5 or 3.5 hours of multi-engine handling. Its then back into the IFR training.
Getting to grips with IFR is hard and I suggest that trying to do those first 2 nav exercises in an aircraft which is going like the clappers is putting an enormous load on yourself. It is better to do those couple of navs in something slower and more familiar, especially when I recall that one of those navs is from PMQ to TRE then KMP and back to PMQ. All short legs with a high workload.
By way of interest I struggled with my first navs in the Baron and it wasn't until the third or fourth that I started to get my thinking far enough ahead of the aircraft to be able to feel confident that I was going to be able to complete the course.
What this ramble is really saying is that trying to do the whole course in a Baron is not a good idea.
Best of luck with the course and you can look forward to a great sense of satisfaction on completion.