LX7 & PL2 owner weighs in
Hey, Droogie -
I currently own both an LX7 and an EPL2 so I have a few opinions, but let me preface it by saying that though I've never used a G3, I've fooled around a little with its big brother, a GH3, so my opinions may not be exactly what you are looking for. But what the LX7 does share in common with its larger Panasonic brethren is a few more physical controls than the Olympus EPL2 has. The LX7 has an aperture ring (very useful for Aperture-priority shooting) and a small jog/click wheel that can be used for a variety of other things, including altering shutter speeds (when you're in Aperture priority mode) or altering a number of other shooting parameters. Other physical controls include what looks like a 2nd smaller click/push wheel that only controls 2 things (the built-in ND filter, and focusing when one is in manual focus mode); and a few other cool changeable physical settings on the lens. These include a way to rapidly change the sensor format (from 3:2 to 4:3 to square to 16:9) by merely shifting a lever; another very useful click lever to change from AF (fully Automatic focus) to Macro AF (a very very cool mode with Auto focusing down to very close macro distances) and finally MF or Manual Focus.
Then of course there are the usual dials atop the camera and on its rear - PDAF - AL/AEL lock - playback - etc etc etc. In many ways, most of these buttons/knobs on the LX7 are not unlike similar dials or switches or knobs on the EPL2.
The biggest differences are in changing various other shooting modes and parameters. If you're already familiar with Panasonic Menus (your G3), your learning curve should be a lot less step than it was on the EPL2. There are a lot of similarities between the higher Lumix models and the semi-lower-end compact LX7.
But - and this is where we get into truly subjective and individual territory - I think, honestly, it all depends on your tastes and abilities. I find the LX7 relatively easy and logical to use while shooting - but then again, I also found the EPL2 pretty easy, once I got the hang of Olympus's menu system - a system which, btw, is fairly complex and complicated, with menus and submenus, and some things hidden in places where you might not ever look. But, honestly, in day-to-day shooting with the LX7, in spite of having a slight advantage of more external and easiliy changeable settings or click wheels - to really make the most of the LX7, you also have to dive into its Menu System ---
Is it easier than the EPL5's menu system?
Maybe a little. Especially if you're already more familiar with Lumix menus from your G3. But it's still get enough complexity to it for there to be a learning curve. The Aperture Priority mode btw which is one of my favorites is relatively easy to use on the LX7 - the combination of external aperture ring and an easy click wheel to change shutter speeds - makes it a little easier than the EPL5.
But the LX7 has its complexities too. One of the mode settings I like is for 'Creative Controls' - which allow access to a number of clever, powerful filters and settings to create interesting in-camera JPEG's. My favorite among these is what Panasonic calls "Dynamic Monochrome", which yields beautiful & contrasty b&w images. But the catch is that the controls for any of the different 'Creative Control' settings (including Dynamic Monochrome) - involve using a click/jog wheel to access a new icon based menu where you have to move slider bars that raise or lower exposure or apertures or saturation or contrast. It's designed to be sort of a 'dumbed down' control process for people for whom the concepts of apertures or shutter speeds are too complex - but, ironically, it takes a certain amount of thinking to figure out how to really access and use the various menus, controls and sliders in this mode to really get the most out of it.
Bottom line - in some ways the LX7 should be both easier and a quicker learn for you, coming from your main workhorse G3; but in other ways, it's got some complexity to it.
Finally your other question - whether or not the external EVF is worth it? Well....guess what? I have them for both the EPL5 and my recently acquired LX7 and in my admittedly subjective opinion, it's more than worth it. Not merely for the onus of trying to see the screen on sunny days - but because the Panny EVF, like the Olympus, gives you a much better way to look at and assess your subject, your lighting, etc etc etc. One minor note: though the LX7's EVF is very good, I don't think it's quite as good as the Olympus's. But, that said, it's invaluable to have, in my opinion.
Hope some of the foregoing helps. But the truth is, a camera which truly 'works' for one person....won't always necessarily 'work' for another, so take all this with a grain of salt and then, if you can, try to find a way to check it out in person. That would be invaluable.
Good luck!