Kirk,
I use a X5s with several Oly lenses and have had the chance to test a X7
set for a couple of days, since then we own that as well.
First of all the most optical difference occuring to me is:
The X7 lenses are true prime lenses. they nearly have no saggital coma and very minor chromatical aberration. I find the pure optical quality of these lenses stunning.
this is to my opinion quite important as only ACR allows for lens corrections (in PS or AE). ACR enhances image quality of Oly lenses very well, lens corrections here are welcome.
with the X7 lenses this is not much needed or can eve be avoided. Since Davinci Resolve (which is the only host that can fluidly handle CinemaDNG) does not allow for lens corrections X7 footage does look better here.
The rest in brief comparison:
X5s:
pro
# great lens range of all sorts
# slightly lighter, allows for a bit more flying time
# even a zoom available
# smaller packing size
# blends in well into RED, Alexa, Blackmagic Footage
# GH5 ish looks and bokeh
# all lenses can be used with Blackmagic 4K pocket which is a stunning camera by itself and makes a great combo with
Inspire 2 and X5s
# fairly good stills quality
cons
# less dynamic range (fewer stops)
# shooting sunsets they burn out
# no ProRes RAW option
# saggital coma and chromatic aberration always an issue
# like GH5 high readout noise at low light
X7s:
pro:
# absolutely prime lenses
# saggital coma and chromatic aberration a non-issue
# great DR, easier color grading overall when light gets challenging
# blends in very well into RED, Alexa, Blackmagic Footage
# amazing at low light
# sunsets don’t burn out
# gimbal has to my experience a bit less drift
# great sensor quality, less noise at low light
# great stills quality
# 6.2 K Prores RAW
# 6.2K stills!
cons
# pricetag - but again, these are true prime lenses, would cost 3x more elsewhere - in fact for their great performance they are decently priced
# focus calibration nag quite often with 50mm
# bigger lens package size (when travelling)
# only option on the wide end is the manual venus optics/laowa, Go 4 sometimes goes nuts with that manual lens, Litchi is an option here
# built in ND4 of not much use with the 16 mm
# slightly shorter flight times
did I forget something?
I say both X5s and X7 have their merits. pure optical quality on the X7 primes however is unparalleld. but they are just 4 lenses plus a manual one that needs preset aperture and fixed prefocus.
lens range and options on the X5s is great, and footage quality is still excellent (except burnt sunsets). if you shoot much lowlight however, X7 is superior. as well, Prores RAW is great, bummer it isn’t available on X5s.
if I travel lightly or have to Hike the Inspire I often prefer the X5s especially combined with the new Blackmagic Pocket Cinema 4K it’s a great, hard to beat package for the price.
if I have to shoot the best overall quality especially lens-wise, I grab the X7.
cheers