Quick Sparging Question...

I started doing 10 gallon batches a few rounds ago. To accommodate the extra grain, I've been mashing/laughtering with a converted 15 gallon keg (the same vessel I use for the boil). This is an annoying process, having to clean the spent grains out before I can start the boil, so I was wondering:

Has anyone tried using two separate 5 gallon coolers to mash, and then combining the worts for the boil? Will this reduce efficiency? Or change the flavor of the finished beer?

I like this idea because it will speed up the sparging process too. Thoughts?

I'm no expert, but it sounds like you're doing two separate batches, then mixing them while in process. While a pain in the but, I think it will work.

Just get a cooler that big enough to do 10 gallons. It seems silly to set up 2 mash tuns when you can just make a big one.

+1 Use a 10 gallon cooler and be done with it. IMHO