Google+ is a great platform. I love it as a community, and it makes posting my thoughts and discussing them with others super easy. I've been using Google+ on my Nexus 5 increasingly these days as I travel, and there's one problem that I keep coming back to every single time: the number of toolbars and other horizontally-oriented information in the app makes it feel like I'm peeking through window blinds at my feed in landscape mode.
Here's a quick image showing the normal landscape interface, mid-scroll.
So from the top, we have the hamburger menu, a spinner, a completely superfluous people icon, and the notification button. Oh and an overflow. Moving down, we have a giant blue box alerting us that there are new posts (exciting). Then we have content. Then we have a giant "share" bar with specific buttons for Photo, Location, Mood, and Write.
Before discussing any alternatives, let's look at what's actually visible if you take away all the chrome.
What part of that, in this example, is actual fully-visible content?
That's not a lot. Of course, if you begin scrolling down, the share bar and "new posts" bar disappear.
But even then, the viewing experience isn't great.
What would I suggest? Mini cards.
Google Play Newsstand has mini cards, and they're awesome. You can quickly see stories, decide if they are interesting to you, and see the full thing if you want it. Of course, Newsstand doesn't use mini cards in landscape mode, but it could, without sacrificing any information density. Ideally, the app would also be more immersive in landscape mode, eschewing the nav bar and either hiding the status bar too, or making it transparent.
Of course, there are some remaining considerations with this approach - the current Google+ app has a live preview of the three latest comments on a given post - that would not fit on mini cards. The user would need to expand the card to see the comments or to add their own input. I think this could be done inline, without going to another page in the app, but it may be a deal breaker if the Plus app needs to look constantly dynamic and moving.
This isn't the only solution either, but if I'm going to complain about peering through a window to see content, I'd like to offer a possible alternative.