We have used Keyence PLCs for many years since we get a lot of machines from Japan. Keyence has only been supporting them in the USA for less than a year. Their staff is young and inexperienced, the manuals are hard to read as the translations from Japanese isn't very good. They keep telling me that's their biggest complaint and they are constantly improving them.
As Bill mentioned, it's very similar to Mitsubishi. I do remember Omron being klunky like that but they have come a long way. The Keyence software (KV Studio) can take some getting used to as the translations in the software are much like the manuals.
The PLCs are very functional. You get a lot of bang for the buck, speed, memory, fieldbus, motion control, specialty modules, etc... They do compare with any of the big boys out there, in my opinion. The software contains the configuration utilities for all of the above.
If your project is in a hurry you may not want to chance it. If you time and can afford it, get one and play around with it. It appears they are really trying to push these units into the field so you can probably talk your rep into a lower price.