Regular Formulas vs Array... err... CSE formulas

Hi! This is my first post, and I'm rather slow, so please bear with me if my question is stoopid :)

I seem to have the opposite problem everyone else does, I mean, I use those CSE formulas absolutely everywhere, like, when I have two rows, and in the next row I have to sum them up, instead of filling the row with something like: =A2+A3 till =Z2+Z3, I simply place an array formula =A2:a3+Z2:z3. Yeah, I'm weird, I know!

My question is, is this weirdness of mine costly in terms of efficiency? I'm making this HUGE spreadsheet financial model thingie, and it's starting to eat resources, I have to frequently close other windows when working on it, and I'm beginning to wonder if that's because of my CSE formula usage everywhere.

So the question which I could've asked in one simple sentence but took three whole paragraphs to ask is: Are CSE formulas more inneficcient than regular formulas, and I should try to limit their usage, or can I keep being weird and look for the solution to my resource problems elsewhere? :)

Thanks and sorry for my longwindedness

Vannie