Generally proximity to the wall will cause a loss of perceived depth of the soundstage that good monitors can provide, so you gain yourself some bass at the expense of imaging.
kn
Plugging rear ports of "bookshelf" speakers?
I did a search here on A'gon to try to find out what the reason for this would be, and I take it to tame unruly bass? Would plugging the rear ports make a speaker less particular about placement? I would think that if anything, plugging the rear ports would mean the speaker could be moved closer to the wall, but I find that I am often mistaken about my preconceived notions.