I agree with Pinky, and would even argue that Allergy should be put up there as high as Cards or GI in terms of tier and level of competition.
As far as being the "poor man's derm" -- I'm not so sure about that. Busy allergists make $350-400k in the Southeast U.S., which is where docs still do the best in terms of earnings. From what I understand, this is as good if not better than many Dermatologists. Why is reimbursement so high? First of all, an Allergist has at least three billable things going on at one time -- seeing patients, skin tests, and allergy shots. Second, skin tests are still reimbursed very well, like a procedure for the most part. Plus you can do a bunch at one time. Hence, volume.
There are only 60 Allergy spots in the U.S. SIXTY! I train at a top ten IM program and there are at least one or two applying to Allergy this year out of the R2s and R3s applying to fellowship this year. Multiply this out to the top 25 IM programs, and you have a good 30-50 presumably very competitive applicants. That doesn't count the likely scores of others from other IM programs who are just as good.
Bottom line -- Allergy is becoming VERY attractive to IM grads who want a good lifestyle and don't care about procedures.