The benefits of the X-MTM and X-SLS are that they are floor standing models, so no need for stands. Plus, either can be front or rear ported if near-wall placement is a must.
The X-MTM will offer a little more clarity in the mids and bass than the SLS thanks to each woofer doing half the work, but they are also taller, deeper & heavier than the X-SLS.
Alternatively, there's also the X-Omni, which is about the same price as the XLS (the price on the site is a placeholder, so you'll need to call danny directly) but it definitely requires a minimum of 3ft from the front & side walls.
Ideally, I'd say go with the MTMs and a sub, but realistically, a pair of X-LS or X-SLS with a sub will be an equally fantastic pairing.
