Honestly, I whenever I think about TS4 toddlers, I always wonder what age they were going for. It seems like they're meant to be around 3, though certain elements of their skill progression make that seem off. But at the same time, I never played TS2 or 3 so I don't know what age those toddlers were meant to be either. I know that they crawled, but looking at video clips of them, they looked too old to be crawling to me (though that could just be the design). But I suppose that's off topic.
As for my answer, since we don't have that stage of a crawling, fully dependent, not tied to a bassinet life stage, it makes me long for one. I don't like how independent toddlers are in that they only need help with the potty skill and can otherwise take care of themselves (Unless they have the independent trait). Now, if we had better babies *cough like Freeplay's* that could learn to crawl, stand, walk, etc; I wouldn't mind older toddlers since it would feel like a natural progression. But if they're going to continue with babies being either an object or not allowing them to learn to crawl, I'd like much younger toddlers.