I'm on my 3rd season I'm my Mojo HD. Honestly, even with all the new offerings, I feel no need to replace it. It climbs -amazing- for a 160mm bike, stays high in its travel (which I like). It's also a convertible bike where when I want I can use a shorter , lighter fork, and a short shock for a stout XC ride.
The new HDR drops .5lb off the old HD, has some tweaks to the linkage to accommodate the new rear triangle, to better accommodate the 650b option.
Re: 650b. If you do choose the HDR, it is convertible to 650b with limbo chips and a short shock. Similar to the old HD (which could run 650b in140mm mode), but the HDR gets better/proper modern geometry in 650b, without messing with HA and stuff. The beauty of the DW, is that shortening the stroke of the shock in 650 configuration does no compromise the performance (although it adds a slightly more progressive feel-which is nice in this configuration)
Now if you are shuttling Moose or Mt 7 all the time, Mojo with an RC4 or the Nomad with a coil. They do feel different on the descent. I'm not sure if the Nomad is lower and longer, but it feels lower and longer, on my limited time on a borrowed Nomad c. They both are happy with a 180 fork as well.
Ibis has amazing customer service. I've had good long conversations on RC4 setup via email, which I though was a bit unusual:-)