I guess this post is from several months ago, but if you're still around, or if anyone else is wondering the same thing, here are my impressions so far. I'm finding it workable, but it's been a bit of a struggle. Here are some tips:
Do NOT use the realflow lightwave plugin to import realflow meshes. Not only is it slower to replace the meshes on each frame, it will frequently reset the surfaces back to default, or even switch the surfaces between multiple meshes that you have loaded.
The workaround for this, which is working for me so far, is to export your meshes as .lwo files (setting is available under Export Central), create and save your surface in lightwave, then use this little app to apply that surface to the entire .lwo sequence:http://www.lwplugindb.com/Plugin.aspx?id=87fdffbe
Then load the first object of the sequence into LW and use LW's native object sequencer to replace the mesh for each frame.
I don't think this workflow supports motion blur. You probably need to use the buggy Nextlimit plugin for that.
Also, you can ignore all the RealFlow Renderkit stuff that NextLimit has been touting. They've said that it's simply not worth their while to bother making it for Lightwave. Too bad this pretty severe lack of functionality doesn't equate to a discount for Lightwave users, but I guess separate pricing isn't really possible when the plugins for different apps are freely available.
Anyway, apart from these annoying workarounds and lack of features, it's completely workable. I'm using a computer significantly less powerful than what you're using, and while I'm not doing anything too crazy, I'm still getting decent results.