PEDS
Pros: Get to work with kids, varied pathology, Great Job Market and Job Security in otherwise ophtho-saturated areas, chance to be as comprehensive as you want (amblyopia, strabismus, ROP, cataracts, plastics, glaucoma, etc.).
Cons: Lower overall pay, liability issues of dealing with children (esp. ROP), screaming/uncooperative kids, the parents (sometimes), cool ophtho instruments/technology not quite as applicable.
COMP:
Pros: Don't have to work with kids, higher overall financial ceiling, lots of cool tech (cats, iols, lasers, etc.), probably more surgical time then Peds.
Cons: Have to work with adults, job market, competition, declining reimbursement.
The biggest difference is obviously the patient population. Like kids and can occasionally stand the poorly behaved one? Peds is a good choice. Don't like kids? Wouldn't think about Peds.