I am going to be a first time grannie in July. Iwant to buy the carseat for my granddaughter to make sure she has the best. Now my youngest is 4 so i haven't had to buy an infant seat in over 3 years. What do you think. Mom definitely wants an infant seat so i have been researching and like the graco Snug Ride but what is the difference between the 30 and 35 besides weight? do both have the seatbelt lock outs for the base? What is you recommendations and/or experiences?