Although I generally prefer the sound of Maggies to MLs when it comes to the models that are available used in your price range, I will point out that in a tightly-spaced HT setup, the curved panel design of the MLs may be preferrable for it's wider-angle listening window. I'm not convinced that dipole radiators are a good idea in smaller rooms (though yours might not be too small, depending on the layout and setup), and the answer to your placement-sensitivity question is yes, panel speakers can be more prone to response anomolies than box speakers if not optimally positioned. Additionally, you will need to satisfy yourself that a small panel speaker won't limit you too much dynamically if you like to run loud, and that your amplification is up to the task of driving either a relatively insensitive load (Maggie), or a high-capacitance, low-impedance load (ML), both of which can be more demanding and less forgiving than an average dynamic coil box speaker load.
