I, too, appreciate the nostalgia of the SUIT, so I had to have a couple. You can get tritium vials & install them to illuminate the aiming pointer. This works great.
From a shooting perspective, I'd say they're OK. Dismounting from the top cover resulted in loss of zero, & I am skeptical of the robustness of these systems for practical use/abuse. The aiming pointer & low magnification are not meant for precision work, by most modern standards, but are intuitive & I can see where they'd be advantageous in certain conditions.
In summary, I highly recommend getting one for a range toy. Once zeroed, mine is plenty good for banging steel @ 200-300. I haven't tried further.
I'll see if I can work in more T&E with mine, soon, & report back with pictures & a write-up. There's surprisingly few, detailed, reviews on the SUIT.