I had the MMS 160 with HDF T zoom eyepiece out a couple times this weekend. I found it most convenient to just keep it in hand using a wrist strap as a safety. Surprisingly, field of view was not much of a problem since low power is <7x. The little image stabilized scope felt good and was in no way burdensome to carry. I am used to older style Canon IS binoculars where you hold a button down for IS. I found myself leaving the IS switched on longer than I intended and I fear I will have to adjust my habits or run through a lot of batteries.
In actual use I found the scope somewhat fiddly at higher magnifications. From low power (7x) to about 10-12x it was easy to get on target and focus either with or without the IS. Turning on the IS added to the visible detail especially in the 10-12x range. From 13-20x I found it more difficult to get a good focus, either without the IS or with the IS turned on. Unless the scope is held quite steady, there is a vibration to the IS mechanism that makes sharp focus difficult. This is most noticeable at higher magnification, so some of the advantage of the IS is lost where you want it most. If one is panning at all, it seems that the vibration and loss of detail will be present. Also, as the magnification increases there are issues with losing contrast unless it is quite bright, and I have been using it in both bright and overcast conditions. Getting the eye cup adjustment just right with changing magnification is also a small challenge. This is a bit more critical for a hand held scope. OTH, to me having a range of magnification is part of the appeal of the MMS 160. The sweet spot size is good although the edge rolls off and quickly goes out of focus once it starts to go. I haven't noticed any serious optical aberrations other than field curvature. I don't find the edge performance a problem at all in the field.
Perhaps I need more experience, but I'm still finding the monocular harder to hold steady even compared to a relatively light binocular. I'm also trying to figure just how it would fit into my kit. It's neither a binocular nor a spotting scope replacement, but it does a little of both. It's not much more compact than my 8x30 binocular, which is a much better performers at low magnification and/or low light. It is much more compact/lighter than my scope+tripod combination (1 lb vs. 5 lb), but the MMS 160 is just not the right tool for viewing seabirds at a distance.
I had thought it would be a "spotting scope light" to bring along to supplement my 9x45 binocular. Now I'm thinking I would like to use it as a compact all purpose instrument. The question is whether the range of magnification and IS is enough displace the excellent performance of my 8x30 binoculars.
More Later,
Alan