If you're getting 50% in a foam bator with fan. On your own, not shipped eggs, then you need to tweak YOUR technique and equipment before it's the bator's fault. 80-100% is possible in a foam bator. Calibrate your thermometers, use a "fake egg" internal temp type thermometer, calibrate your hygrometer. Do a run... see what you get when you're sure your thermometers are working. Then bump the temp up .5 degrees and do another run. If recalibrating and increasing temps slightly - as well as monitoring internal egg temps don't get you a bump in production then yes, another bator.
But often it's equipment and technique - rather than incubator.
You didn't say whether you're dry hatching or normal hatching or whether you have tried both - those are also considerations.
That makes three things that are all on the operator and not the bator. If you dry hatched. Try a run normal hatching.
But change things one "group" at a time.
Equipment - calibration and "internal temp" monitoring.
Then if you hadn't tried an alternate humidity - try that.
Then if those don't yield a better hatch rate, or do a little, try bumping the temp .5 degrees.
If and only if all those get you the same or a lower hatch rate would I blame the incubator and change.
Or if you just hate the cramped foam, small view, have to take the lid off construction - by all means switch...
For small bators, the best is
brinsea - the Octagons for 20 or 40 eggs and the dinky but accurate mini's for tiny batches. They offer differing levels of "automatic" for significantly different prices. Read the details.
But for the money of a fully automated
Brinsea, a Dickey or a Biblis (lol dude we need a name) are the better deals and you can run small and staggered hatches in the cabinet bators without affecting hatch rate.
Me, I'm saving for one from Cbiblis, and I have a Working Cabinet bator and a working homemade bator. Both with good hatch rates but his is OMG prettier.