Darth Lefty 

I ordered a Timberjack. So, to summarize...

I wanted an up-to-date mountain bike (short rear end, raked out steering, short stem and wide bars) whose frame had dropper post routing and lower rack mounts. You'd be surprised how many times these features are mutually exclusive. There are a lot of bikes like I wanted in the price range I wanted that just didn't have the rack mounts. I was willing to buy some extra parts to mount the accessories. I had some requirements on the build, but that was the gist. I expect to upgrade the components once the bike is done with kid duty and becomes a full time mountain bike again.

I found the following candidates and here are some notes.

Salsa Timberjack won out for a few reasons. The REI availability winds up being a great deal... eventually. (Nearly all the money back is dividend or gift card). The frame is only on its second model year and it's Boost-spaced with Salsa's modular dropouts, and it can take a wide range of tire sizes, which means, in spite of the rapid change in MTB parts, it will last a while for wheelset and drivetrain upgrades. The NX model I picked is 141 QR and that means it will take the trailer hitch no problem, but it will be able to take 148 thru axle, or indeed it would take a 142 thru or 135 QR, with a change in chips. It's missing the upper rack mounts so I'll need a rack mount seat collar. The kid seat is going to sit a little high.

Surly Karate Monkey and Krampus frames can work. There are some issues with the stock builds that would cause some extra work. Some versions have cable brakes that interfere with the rack, but hydraulics are ok. Some versions have thru axles which require a special aftermarket thru axle to use the trailer. The factory wheelset (2in rims and 3in 29er tires) on the Krampus are too big to clear the rack but it would be fine with somewhat smaller. The biggest problem I had with these bikes was the price tag. The complete Karate Monkey is $1500 and it seems only a little higher spec than other bikes here that cost under $1000. Nothing else I shopped at that price had a rigid fork. Some other Surly models would probably also work but they were all more heavy-duty than I wanted.

Trek Roscoe and X-Caliber would have been strong contenders if they were in stock. Marin Pine Mountain looked pretty good. It was missing the dropper routing. Neither of these frames can be upgraded to thru-axles but there are ways to use some thru axle wheels in the "141 QR" mode and both frames are fairly standard for suspension upgrades.

REI Co-Op DRT 2.1 would have been a contender if it came in a lower spec and brighter paint. I can understand selling bikes in flat camo colors, it just doesn't appeal to me personally.

I'm looking forward to kitting out and riding my Timberjack and reporting back how it works for me.