Well, that's good to now, I had no idea it would last that long.

yes, it does last that long when applied properly.

I can run my printer for about a week on one application.. depending on the parts being printed.
I also move parts around on the bed so I am not using the exact same spot over & over again - gives the most recently used spot a chance to refresh itself a little.  (again, this kind of depends on what is being printed)

only takes a minute or two to freshen up - just cover moving parts with rags, spritz the warm bed (about 60c) lightly a time or two, and then heat to full temp and print away.

once you do need to clean it off and do a completely fresh application, Windex makes short work of the hairspray on glass.

I have seen many using glass, yes it would be inherently flat.  Not a fan of having to use tape of spray every print run, or even every few runs.  Due to time and mess.

I am printing ABS, bed at 100 C. 

I have found the main problem I am fighting with this go around, is the warp - I place prints in different areas of the build plate to spread the wear and tear.  But I began to notice how some prints would come off nicely, some would be stuck like concrete, some even a little too loose.  Found a few settings in Cura that make a good adjustment for the adhesion.  That's when I got the idea to do a run with a couple parts in several locations, and identified the warp correlates to the ease or difficulty in removing the prints.

Just an FYI hairspray is usually good for 20+ prints before it needs to be reapplied then it just needs a quick refreshing spritz. There is a reason glass and hairspray is the go to for most users that use a heated bed. As for the warp this is an issue that most users have except those like me that have gone out of the way in effort and cost to prevent it. The best you can do is find a happy medium between the high spot and low spat and use that as your leveling value.

I am printing ABS, bed at 100 C. 

I have found the main problem I am fighting with this go around, is the warp - I place prints in different areas of the build plate to spread the wear and tear.  But I began to notice how some prints would come off nicely, some would be stuck like concrete, some even a little too loose.  Found a few settings in Cura that make a good adjustment for the adhesion.  That's when I got the idea to do a run with a couple parts in several locations, and identified the warp correlates to the ease or difficulty in removing the prints.

.015" isn't much better than what the OEM plate seems to be.  Have to think about how I can measure the curve in my OEM plate.

https://www.ebay.com/itm/IDE-Makerbot-R … 51fc210ffb

https://www.ebay.com/itm/IDE-Flashforge … 3ac47e2ee6

As a bonus it gives you more usable space in the  X axis.

there are other vendors that sell jig plate as well.

So I ran a test print of small parts, locating them at the center, and the 4 corners.  The center ones were stuck pretty hard, the corner ones were much easier to peal / pop off.

Hmmm....  Put a straight edge on the plate - yep, it is high in the center, lower at the edges, like it sagged. 

  This explains an earlier problem I had with a build where parts near the edges would loose adhesion, and parts in the center were difficult to remove.

So I am thinking...  I could get a piece of 3/8" or thicker aluminum plate, [if I can find someone selling with a flatness spec.] and solve this problem.