I have all 3 here now but have only tried 1 out as yet (i've mainly been playing hl2vr and fo4vr, can't use them in these). I tried the sanlaki sleek magnetic. It's not bad but there's a bit of occlusion where the gunstock covers the top of the right controller ring, it makes long distance scoping slightly inaccurate - your aiming may drift slightly. I will try out the other 2 soon and get back to you.
Edit: I've just tried the BowkVR playing Onward. It is really good, better than the Sanlaki. It requires 2 mins to assemble, it's very light and has no drift, long range sniping is pretty easy.
I haven't tried out the ModusR yet...i opened the box and it looked a bit complex to setup so i may just sell it as I'm already happy with the BowkVR.
ps when I ordered the BowkVR I ordered the version without the optional rifle butt, but then changed my mind so emailed them to request it, asking how I could pay the extra $20 it costs. James from BowkVR said don't worry about it he'll just add 1 to the existing order, so they saved me $20. Great customer service.
Thanks for coming back on this, that's really to hear. It's mainly Pavlov that I'll be using it for, I tried Onward (standalone) version and found it difficult to see in the distance due to the resolution or something. Was going to get the PCVR version until I discovered they have dumbed it down.
I'll have a look at this BowkVR one. Cheers!