Well, let's see. I think that the critical care experience (or at least, the EXPOSURE to the critical care unit and its goings-on) will definitely give you a tiny boost; you'll know more regarding what to expect, the dynamics of a critical floor vs. a non-critical floor, etc.
On our units, we use basically the same vents, etc. that are used on the adult floors; they are just set differently to be appropriate for the babies. Our RT's work on both the adult and neonatal units (they float, but we do have a "core" staff of about four that always get placed in NICU), so the differences can't possibly be that vast (although I'm not an RT!) as far as basic equipment, etc. is concerned.
We use traditional vents, oscillator vents, nitrous oxide for the babies. We have trachs (these are exactly the same care-wise as the adults, as far as I know). We have Peg's, use the same Jelco catheters for IV's, have OG/NG/NJ tubes, etc. just like the adult units (just smaller, or perhaps a different brand, but care is virtually the same). We have the same monitors but different pulse oximeters than our adult units (at my hospital; may be diff for you). Then there are pieces of equipment that are COMPLETELY different than the adults- like bili lights (crap...I'm tired...having trouble thinking of things to list today! Forgive me!).
On top of all the similarities, there are some very distinct differences in diagnoses, treatments, allowable values, etc., but at the same time, metabolic acidosis is acidosis in babies AND adults, know what I mean? The organs are still the same, but sometimes symptoms may be different, or occur in a different order, or not happen altogether. Meds are pretty different, and are in nearly microscopic amounts sometimes. However, we still use Versed, Morphine, Ativan, Heparin, Insulin, Dopamine, Dobutamine, etc. Is that making sense? (Sorry; I'm REALLY tired!) Different. Same. Complicated!
Are you considering teching on an adult ICU? You said you weren't a nurse yet; I'm guessing here. I think that if a position in the NICU isn't available, and they have nothing in the well-baby nursery or mother-baby (which, IMO, are a TEENSY bit more applicable than an adult ICU), here are some other suggestions. Have you considered working in a Children's hospital or Pediatric ward? Frequently kids who end up in those places were preemies, or have a history stemming from birth, and you can still learn very valuable things there. Well Baby nursery is great (as is Mother Baby) because when you're in the NICU, you're still handling things like feeding, changing diapers, restocking things or knowing what type of equipment is used, and lots of parent teaching (newborn care, breastfeeding, infant safety, etc.).
If the only job available to you is on an adult ICU, I say grab it and enjoy! Learn as much as you can. You may love working with adults and never want to leave.
At the very least, you'll learn about normal vs. abnormal conditions, equipment that you may be seeing, rationales for interventions, etc. I always say that no experience is bad experience. You can always take away something valuable.
Hope that helps a little! Yawn!!!