CGI would at least give you more variety. I'm impressed with the craftsmanship, but the decision to make every transformation be:
BOX MOVES!
NOW IT MOVES BACK TO WHERE IT WAS!
CUT SO WE CAN PUT IN A DIFFERENT BOX!
BOX MOVES AGAIN!
NOW IT MOVES BACK AGAIN IN REVERSE! AGAIN!
Practical effects can be just as distracting. In both cases, a little imagination and creativity is needed. For example, the facehugger scuttling towards Ripley and Newt in Aliens is still amazingly realistic, and it's basically rubber over a weighted axle connected to the legs with the whole mess held up by wires.
I just saw Aliens on the big screen, and everything still looks fantastic. With I think the exception of some optical effects (blue screen?) but that movie hardly had any of those. Looks like 99% in camera.