I have used one for about 6 months or so on my ultralight rifle. It matches well with it. Have now a couple hundred rounds down it (pales in comparison to Form's round count). Dialing out to 600 and back on multiple occasions and the dang thing comes right back to zero every time. No zero stop and the turrets leave a lot to be desired. The current reticle choices are dismal at best. Basically for a dedicated dialing scope I'd go the 30mm tube size version of SWFA. Not cause the ultralight has let me down, just the turrets on the SWFA 30mm scopes feel much more solid and I can install zero stops on them which is a huge bonus.
If lightweight is more important that being able to dial then yeah the SWFA ultralight is your huckleberry and its perfect for my uses on the rifle I have it on. But if I am gonna dial on the regular I suck it up and use a 19-24 oz scope.
In the past 2 years I have purchased the following:
Nightforce NXS 5.5-22
NIghtforce SHV 3-10
Nightforce ATACR 7-35
Nightforce ATACR 4-16X42
Nightforce NX8 2.5-20
Nightforce NX8 1-8 (didnt buy this one just got to use it for a bit from a nice guy to try it out)
March 3-24X42
Kahles 624i
Vortex Razor AMG 6-24
Bushnell LRHS 3-12
Bushnell LRHS 4.5-18
Bushnell DMR 2
Bushnell LRST 3-12
SWFA 6X
SWFA 10X
SWFA 3-9
SWFA 2.5-10 ultralight
SWFA 3-15
I'm liking missing some in there. But what have I learned?? For MY uses the scopes listed on the bottom of the list do everything I NEED. The other scopes have some cooler features like illumination, a better designed zero stop, come cooler lines, and these will certainly yield MUCH more instagram cred
But for less than $200 a 6X or 10X would likely do all I need and if those don't and I'm feeling variable
Then for less than $500 a 3-9 or 3-15 variety suffice just as well for MY uses at many scopes that cost 4-6 times more. So come this black friday I will finish off the rest of my rifles with SWFAs and when the little ultralight comes out in mil/mil with a Mil-Quad reticle I will be getting two of those as well for my 2 ultralight rifles.