Transitional spots are usually more difficult to match to because a higher percentage of the applicants come from Radiology, optho, derm, anesth, etc..
It really depends on what location you want to apply to. So if you want to apply to Southern California transitional spots, it would be much harder than somewhere in the midwest. I personally found this to be the case. I received a higher percentage of Radiology interviews in SoCal than I did transitional interviews.
If you can only do transitional interviews, make sure you apply broadly--try to apply to the same places that you will apply for radiology--and try to arrange to interview that same day or the next. It will help a lot with plane fares, hotels costs, etc..
Hope this helps.