There are MANY advantages to doing the PCA route!
I work in the medical ICU of a very large hospital, and can tell you first-hand that PCAs get priority hiring consideration over almost any other candidates; after all, the managers have had two years to evaluate the work ethic, intelligence, timeliness, professionalism, and skills of people who've worked as PCAs during nursing school
The "critical care nursing" experience requirement is waived for those folks, too; they would otherwise never be able to get into Critical Care as new grads.
Added bonus: working as a PCA and then getting hired into the unit gives you seniority over other new grads, which may come in handy when it comes to things like shift assignment and vacation scheduling.
Ours make about $12 an hour - floors and ICUs alike, but your mileage may vary.
Final plug: Every nurse I know who's done it swears that it was extremely helpful with their education.