In hindsight, the biggest issue I ran into switching keyboards was that I was too ambitious playing around with the key configuration. The configurability is a big draw but I took for granted that I had already built up years of natural tendency for certain things - which thumb I use for space, preferences for Ctrl/Alt/Command/Option, for Shift, etc.
The default for these keyboards probably don't 100% align with what you're used to, so you should directly map what you're doing currently over to the keymap of the keyboard and then you can fiddle with making it yours over time.
I will say that if you're not already a touch typer, then a split keyboard is not going to help and it will be more difficult to get used to.
edit: also, if anything, going columnar helped me actually consistently hit number keys!