Are you referring to cellular reception or WiFi? I'm assuming cellular. I had a Note 2, and my Note 3 has noticeably better WiFi reception than the N2, specifically with my 5Ghz WiFi at home. As for cellular, reception, my N3 has been at least as good as the N2. I'm not trying to say that you're not experiencing difficulties, but I suspect it's more of a coverage issue than anything actually wrong with the phone itself. It is, of course, always possible.
The *only* problem I've had with the N3 is that nobody can understand me at all on "speaker phone" mode. Annoying, but minor (for me) in the grand scheme of things.