Well I've been very tempted - I have not purchased one. I read reviews on 18v Lithium drills in a mag and then went and played with a Rigid 18v Lithium Ion at HD. HD did offer a 1 battery set up that was like $99 online only, I don't see that one anymore. Their 2 battery deal is $187. They are 30 minute charge times and everything on the drill is supposed to be guaranteed from life from Rigid, INCLUDING the batteries - which, in my opinion - if they follow through with that..... makes the decision for me.
My brother has the 18 volt makita. He bought the combo pack for school. The drill is light weight and powerful and the run times are longer than my Ni-Mh it seems. His drill and battery also weighs about as much as a 14.4v drill with a battery. The ryobi seems like a fairly decent value. I have been more name brand loyal but the Ryobi seems to worth a try.
There was a time, years ago, where the only real choice for high quality battery operated drills was to go with Makita - that was back when the only battery operated device to be had was a drill (at least generally).
In my previous career, it was Makita or nothing.
As a homeowner, that needed affordable tools and was not reliant upon them for everyday use, I tended towards Ryobi.
Now there are a plethora of options, and I would still look for the best cost... mostly because I don't rely on it for my job.
I would certainly lean towards lifetime battery replacement - that is a hard deal to pass up. My only question would be "define lifetime". I know my buddy got screwed with a model line from Sears. Sears discontinued that line because of problems, and he can't even buy a replacement battery for the tool anymore.
Well I have a hard time Sears would guarantee anything more than like a year or so w/o an extended warantee plan. I know as far as their hand tools go - you walk in with a broken ratchet from 10 years ago and you will walk out with either the same ratchet or a comparable one. I was standing in the store when someone brought a ratchet in from long ago - it was so long I'm not sure if he literally got a brand new ratchet w/o any extra cost, or if he just got a really good price on a brand new one.
You are right though - if in 10 or so years Rigid stops making 18v Lithium drills or we can no longer get the batteries for them, which is actually a possibility with technology improvements, I don't know what Rigid would offer up regarding their warantee.
I just take comfort in knowing that it is a pretty sweet drill and, if the battery craps out within the next couple years it is an easy replacement. As far as 10, 20 years... I will get their when I get their. I just know my 18v Craftsman hasn't seen all that much use and it doesn't perform as great as it used to. It's easily the battery, doesn't hold a charge that well. The drill itself is in great condition.
I live in a pretty cold area and my garage gets REAL cold during the winter... I've killed pretty much all my battery tools in the past three winters being here.
The idea of a "lifetime" replacement for batteries is certainly something I will look for when it comes time to replace