Thanks all for the input everyone.
RMROSE - there's two M4 bolts on the underside of the seat stays you can bolt a frame lock onto. Pretty neat, I'd say!
Joe - No worries on the misspelling, the autocorrect of my life. I do like the Otto lock, but this winter bumped the combination at the liquor store with my mitten and it partially removed and locked up and it reset the lock to a random code in -40 and had force it off. I was quite surprised - but then after some internet research it is a common issue for the lock if bumped to auto reset the combination so lost faith in them a bit. If i was far from home and couldn't get my bike unlocked it would be a bad day! Its a shame because I otherwise love the lock.
I think this seems to be the general consensus that they are heavy and awkward to install. I may just wait and invest the $80cad elsewhere for now. It's not necessary for the initial build - perhaps I'll wait until the build is further completed.