Lots of different opinions here. Some of them are not my experience.

If you use a visa service to get your Russian visa, choose one of the specialists that are usually run by Russian expats. They will tell you exactly how to do it, they know all the regs, have friends at the consulate, etc.

The registration on arrival in Russia is something you have to know about. If you get a tourist visa (the easiest) the visa service will get an invitation for you part of their fee. You do not have to stay in this hotel, but you do need a hotel name/address to write on the arrival documentation. It is not cross-referenced on departure. The visa service will also give you details of how to get the hotel registration stamp at a local office (many of them tend to be travel agents) they know (tends to cost about US$30 locally for this). Take your passport to them one day, collect it the next. It will be stamped with some hotel you have never heard of, but no matter. This is much more efficient than going through the OVIR office.

Russian bureaucracy is not normally hard on people doing their own thing, but are more concerned that everything is properly stamped in the right place and that sort of fine detail. Apparently it's always been like this going right back into Czar times.