Got my money on Anderson already. Forrest's best chance is lay n pray which Dan Henderson was able to do to Silva for a round. If Hendo couldn't consistently get him down and avoid being finished then I don't see Forrest doing it. Hendo was a 185/205 guy so he was bigger than the average 185lber at the time also.
The Spider is too quick & will pick Forrest apart on the feet and avoid takedowns pretty well making sure Forrest eats knees when he shoots.
The clinch is Anderson's home which is normally an advantage for Forrest with his dirty boxing.
Yes weight difference may be an issue but Anderson is just too quick & technical with too many skills for it to matter. Remember he beat Franklin 2x (now a LHW), Hendo (fights at LHW), & Irvin so he's fought bigger guys before...with more skills than Forrest.
People are down on Anderson because he hasn't finished fights but his opponents haven't given him a chance choosing to fight scared & not over commit. That's lead to boring fights but ones in which Anderson easily one. Had this fight been after he KO'd/sub'd Marquardt, Franklin, Hendo, Irvin in a row then this line would be around -500 or so. It still may end up around -400 by fight time.