Non-split ortho is silly, but with split layouts I find them vastly more comfortable, especially for the left hand.
The only thing I had to relearn were the keys on the bottom alpha row on the left side, because on a regular keyboard I would tend to offset them by one column (i.e. type C with the index, X with the middle finger etc...) but with an ortho I didn't need to anymore. And the only reason I needed to offset them in the first place is because standard keyboards have such a bad layout for the left hand.
The only thing I had to relearn were the keys on the bottom alpha row on the left side, because on a regular keyboard I would tend to offset them by one column (i.e. type C with the index, X with the middle finger etc...) but with an ortho I didn't need to anymore. And the only reason I needed to offset them in the first place is because standard keyboards have such a bad layout for the left hand.