IMO primes have the advantages of being smaller (but not always) and having a wider aperture available and also of being able to provide better ultimate image quality but you may have to look very hard to see it.
If shooting landscape (or anything else not requiring f1.4 to f4 or maybe even a bit wider) I'd typically be using apertures in the f4 to f8 range and even a kit zoom can mostly match that requirement and once you stop a kit zoom down a bit they're often good, so good in fact that it may be difficult to tell what lens was used. Also the MFT kit type zooms I have are useable wide open which helps in that they don't need stopping down to overcome a fairly obvious weakness wide open as some SLR/DSLR lenses do.
I've been very impressed with the 14-42mm mega ois I got as a part of a kit. It's useable wide open and it's the size of a prime lens. The only drawback is the f3.5-5.6 aperture range which may well be a non issue for many things including landscape. It's susceptible to shutter shock but that should not be an issue on your G80. I've been so impressed with this lens that I've considered buying a new non shutter shock affected body just to use it on
PS.
In fact the 14-42mm mega ois and a fast prime, something like a 17 or 25mm f1.8 and my 50mm macro would probably cover 99% of my needs.