The powerful 10x magnification and use of good quality optics will deliver sharp, highly detailed views at longer distances.
This 10x power in combination with a 36mm objective lens produces a moderately sized 3.6mm exit pupil and thus makes them not ideal for very low light use. However, it is easily large enough to deliver a bright clear image during the day even in poor weather conditions.
Higher magnifications also result in a narrower field of view, therefore the particular characteristics of the 10x36 configuration on this Vortex Solo monocular lend these to being most effective in wide open areas where distances are greater and ambient light conditions are usually reasonably good.
At 15mm the eye relief is perfectly adequate for non-eyeglass wearers. If you do need to wear glasses, it may be a little short and thus your field of view may be restricted. If this is a concern, the 18mm of eye relief on the Vortex Solo 8x36 may make it a better option for your needs.