Please note that this is meant to be a constructive review of the plugin based on my own testing. Some of what I mention may seem harsh to the developer, but it is meant to spur them on to create something better. Hope it is viewed as such.
I have tested PageLines and found it a very good system overall. There are many thoughtful components to it and only a few that I personally would change.
Note: I am mentioning other page builders in this comment, not to advertise them but to provide a clear comparison to back up my comments.
I found text editing awkward to use in some ways in PageLines compared to other front end page editors - and the absence of on-page drag and drop functionality was mostly frustrating.
Editing the text modules off the page in a special modal field slows things down, even though it often shows the results live on the page (I say often because sometimes my changes didn't show up on the page until after I saved and turned off the builder).
This is a text editing disconnect that is slower than other systems out there and, frankly, unnecessary given that there are several front end page builders that let you edit text right on the page, including one completely free one called Live Composer (also available in the Wordpress Plugin Directory), Page Builder Sandwich (not free), Thrive (not free), and others.
Re: drag and drop - The reason I found this mostly less effective in PageLines is that having to move around the various modules using only the old backend page building style kind of makes no sense, even if it is in a window right next to the on-page layout.
I desperately wanted to drag and drop rows and modules on the page, such as can be done by other front end page editors like Live Composer, Beaver Builder, Motopress, Page Builder Sandwich and the like.
Combining the current method in PageLines with on-page drag and drop positioning would be tremendous, however. The PageLines method is particularly good a locating and targeting elements on a busy page overall. I liked that!
Worth a three to four star rating for being reasonably simple to use right out of the box, and for the included full layouts and features that can be just dropped into the layout.
Get that drag and drop thing figured out and the text editing right (imo) and it would be pretty cool to work in.
My suggestion for all developers of page building plugins is to fully examine the competition to see what is already out there, and create something better. What is the point of creating something worse or more complicated compared to something else that already exists?