I think you made the correct adjustment to your workflow. If you use LR you don't want to fight it.
You might want to adjust your LR ingest to automatically apply more sharpening via a preset. Might save you a step in the work flow.
You can make ViewNX render as slowly or likely more slowly than LR while browsing . From the ViewNX2 menu, click View|Viewer|Display Raw Image. Now ViewNX2 will render every image before it displays it, rather than just extract the embedded JPG.
Don't forget to change that back to View|Viewer|Display Preview
The performance problem you have while culling in LR is why a lot of people front end it with something like ViewNX2 or Photomechanic. I would have to do the same. It's all part of the grand compromise required to use some other raw editor other than CNX2. So you are not alone, and you are doing the right thing.
>> I have been using LR for way too long to switch to anything new now. The D800 threw a wrench into things, however.
There are a lot of reasons why, if that was your only problem, you would not want to throw in the LightRoom towel if that was your only problem. You'd be trading for a lot of more complex problems. And that is from a long time CNX2/PM/iMatch user. But this user is buried in his own pile of historic CNX2 edits.