I bought this in 4T for my 3 year old, who is super tall & relatively skinny; by sizing charts she was the height of 4t, but weight of 3T.  This one  was too big, both lengthwise and around the waist.  The 4T speedo fit better, lengthwise through the torso, and still roomy through the waist, but less so.

This is a great product and also better than other brands are....too thin and this is warm suit she loves it in the heated pool, great for the summer too  spf 50 + amaizing....

Bought these for my almost six year old twins for their summer swim lessons and swim outings. Here in the San Francisco Bay Area (California) summer mornings are typically foggy or overcast. This has taken the complaining out of swim lessons!
Also great when we went camping (swimming in a lake), and swimming in the pool on vacation (again, overcast).
Everywhere we go parents come up and ask where we got them!
Comfortable, dry well.
Got size 6 for my average size girls. Size 5 was definitely too snug.
Can't speak for wear and tear yet.

Bought for my daughter to use in swim class.
She gets cold and would turn blue. This solved the problem.
Does not hamper movement, no poking collars or stitches,
and the zipper constantly works.
Yes, it's purple. The picture is really too small to see the
detailing or what the true color is.

We had this in the 1 year size for our son and just replaced it with the 3yr.  He's 20 months and has been swimming since he was 6 months old.  This suit makes him much more comfortable in the water!

My 4year old daughter chose this suit over the Speedo pink thermal toddler suit based on the purple sleeves, and she loves it!  I ordered the 5T because she is >95 percentile in height and I wanted her to be able to grow into it.  It fits OK lengthwise, but she is definitely too skinny for it to fit like a glove, so water does get in.  That being said, it doesn't bother her at all and she even survived night swimming in an 85degree pool with 50degree outdoor temperature.  So far this has worked really well for our indoor swim lessons where the pool is a chilly 80 degrees.  She still gets cold by the end of the 30 minute lesson, but that is probably because she is a bit skinny for the suit and they spend part of their time hanging onto the wall.  I think we will get our money out of this expensive suit as long as the arms don't wear out too quickly (they are regular bathing suit material, so will no doubt fade/stretch faster than the body portion.)  Overall, I am happy with the purchase.