It has been 11 years since I last had a child of crib age. Needless to say, there is a lot that has changed since then...especially mattresses! I did a TON of research trying to find the perfect mattress for my little one, without spending a fortune. I researched almost every mattress sold at BRU, Target, Walmart, etc. After measuring the crib several times & reading countless reviews, I decided to go with this one. The size sounded right, & I really liked the fact that it could grow with my little one & be used in his toddler bed (his crib converts). I received the mattress a couple of days before the earliest estimated arrival date. While it is not significant, I can tell a difference b/w the Infant side & the Toddler side. Some of the mattresses I looked at in stores said 'very firm', but in fact were way too soft to be safe for an infant. This mattress however, truly is a firm mattress! It fits perfectly into my son's crib, with no gaps, & is nice & firm! I feel very safe with him on this mattress, & he sleeps wonderfully on it, so it must be comfortable too! I would definitely recommend this product!!!