So I use OpenScad quite a lot for 3D printer stuff - it gets my vote too. I love making project cases with it. Folks who code are supposed to like it. If you go with scad - a few things I found useful via trial and error:

1) It *does* get boring but.. do define all primitive shapes with meaningful names using modules e.g. lid(), base(), cutout(). I position and size them with global variables where possible, e.g. LED1_cutout(L1cutout_x,L1cutout_y,L1cutout_z etc). You'll be treating any imported STL as a named primitive anyway. Also, I visibly stack them below the model for visual reference. You can hide them when you're done. Seeing them live nearby helps me to keep my head during difference/intersect/union operations.

2) Like any language, you'd want to define vars at the top as you go, but also take the time to add the tiny extra bit of syntax that exposes the changeable value in the constructor sidebar. This sidebar gives you easy sliders, input boxes, drop downs etc to play with. If you can stick with it, it feels like you are writing your project's own little GUI for free (:

3) For primitives and your main model, make an early call during your project what you are going to centre/align-to. For 'curvy' projects, I have stuck to 0,0 for everything, with offsets from centre added as needed. I'll use a global left-corner align for largely square-themed projects. Someone cleverer than me might say aligning everything on a common corner should always be done. Each to their own but for the sake of sanity, I think it helps to decide early on which you are going with.

Hope it helps. Whatever tools you use, enjoy!

Cheers.
Ed