You provided excellent analytical updates, throughout this conflict and the Georgian conflict back in 08' and I'm curious to your thoughts, on RF military forces KIA in this Ukrainian conflict? Not including ethnic-Russian Ukrainian Rebels, Russian volunteers (not enlisted in the Military) or Int'l volunteers..
I think you're in a better position to comment on this particular subject than most on here, so I value your opinion looking at this further.
I think they're low. Very low. Russian forces only get involved in a few key operations, and seem to arrive with what (for this conflict) is overwhelming force. In the case of Logvinovo it appears that a Tank Btln Tactical Group from the Russian 5th Tank Bde was used, with T-72B3 tanks for their standard equipment (the most modern and capable tanks in this conflict so far). Logvinovo was seized relatively quickly, no protracted fighting, and the Ukrainian counter-attacks were very watery. The eventual retreat corridor for Ukrainian forces seems to have bypassed Logvinovo entirely, and the fighting during their withdrawal seems to have been with primarily rebel troops.
Their participation in the destruction of Sector D (Ukrainian deployments along the border last summer) was primarily artillery and UAV. Probably entirely blood-less.
The battle of Ilovaysk is a major grey area. Two T-72B3 tanks were destroyed, and a BTR-82AM also was at the same time, but not in the same location. So during that time it appears that significant numbers of Russian troops got involved in heavy fighting. However the battle was extremely one-sided, ending in the destruction and slaughter of the Ukrainian troops trying to exit the pocket with their heavy equipment intact, even with two tanks down, the casualties would still not have been too high.
The big grey area is the Russian military personnel embedded with the rebels directly. Logistics for the rebels are run by the Russian military, but those don't participate in the fighting directly. Rebel air defense systems (the sophisticates ones like the Tors and Pantsyrs) are Russian-operated, but we have 1 very sketchy report of the loss of one Pantsyr (probably little more then braggery, as no photos, and no substantiating reports surfaced). The UkrAF has no real SEAD/DEAD capabilities, and has essentially stopped participating in this war due to high casualties and low effectiveness. Russian EW and ELINT assets are in play (potentially OsNaz GRU, though regular R.E.B. troops are also possible) but again casualties wouldn't be high, and would be hard to confirm.
My personal estimate (educated guess) is medium double digits (40-50-60ish) for Russian military dead. Not Russian military volunteers who leave their units and join rebel forces, but actual dedicated Russian military deployments.
It's nearly impossible to estimate how many Russian service members on special leave that go to fight for the rebels have died, because there's no way to trace their employment or deployment among rebel formations.
EDIT: A separate thought. A lot of military equipment that must have come from Russia has been found destroyed. In particular this includes BMD-2s and BTR-80s with NVG gear that's clearly post-Soviet of Russian origin. Also recently retired Grad systems that may have come from units that have gotten the Tornado-G replacements. These weapons look like they came from active Russian units, but mostly were used by the rebels. This complicates accurate estimates of Russian military regulars getting involved.