I usually find myself in agreement with Kumagai-san but not on this.
English signs probably shouldn’t be a top concern. If your workforce can’t communicate with one another you’re going to struggle I fear. (I remember seeing an English sign on the road down in Shikoku that said we were coming up to “Toon Town”. We were just passing through a place called 東温市, as I recall, so good luck finding Bugs Bunny if you couldn’t read Kanji.)
The biggest draw for me when considering working for any particular employer would be that they have a talented workforce – that is the people that one works with have valuable knowledge and skills, and the ability to communicate effectively with one another. (Is my bar too low? I suspect it might be exceedingly high?)