All of these guys have given you great advice on these two units, but I feel they may be a bit optimistic of the points system.
I don't think the Bonus Points system is going to be around long enough for you to obtain enough to draw EITHER of these units. The point crawl gets further and further away each year... It's like interest on a home.
If you are just now starting off, you can put in for any unit and when you don't draw, you will receive the same point as when you don't draw the Henry's or the Books... In 15 years, (assuming we still use the bonus point system) max points for the Book Cliffs will be around 21 points... And for the Henry's it'll be around 30. The point Crawl will continue to outrun you on any unit where a lot of people put in... You could luck out in a few years so it may be worth your time... Maybe.
I think the DWR and such are trying to figure out a way to either faze out the points, or possibly create microunits so that more Bonus point holders can draw each year...
I dunno how they plan on countering for the point crawl though... Just seems like the points don't have much of a future...