I didn't read the replies, so my apologies if I comment superfluously.
I alternate between English and Spanish layouts on a software level - simply using the Region and Language keyboard settings from Control panel.
The physical layout is VERY similar to ANSI, the only functional impact I find the Spanish layout has on my English typing is the ' character we use for "It's" etc which obviously doesn't exist in Spanish. The difference in Spanish is more significant, obviously, as you need the accent modifier key to type correctly and the ñ.
Honestly, I don't see any reason for purchasing a Spanish layout keyboard when it is very easy to adapt to using a physical ANSI layout with software level Spanish key assignments.
I have BLANK keycaps on my keyboard, so for me, my brain just switches between modes, which is physically done by pressing left shift and left alt together (it toggles through languages).