I'm looking into a dual side crib mattress. One side is firm for baby and one side is softer for toddler. I'm guessing after a year or so you just flip the mattress over until baby is ready to move out of the convertible crib and into a real toddler bed or larger bed?

Questions for parents that bought one of these...

1) could you tell a difference between the sides?

2) when did you flip the mattress?

3) any recommendations for a sturdy/ heavier dual mattress? I put the Sealy one Lucie's List recommends on my gear list, but am open to other suggestions. Budget max $150

TIA