no drop in stock = lots of cash and no debt

The high spending in R&D as a percentage of revenue is a Red Herring. When revenues go down you cut expenses. That is much easier to do in areas where there is large discretionary spending (marketing/sales, etc.). R&D is mostly headcount. The only way to cut that is a layoff which, so far, has not happened. I'm sure when revenues gets back to normal levels the R&D number will hover in the historical mid teens.

Now the question is where to put your money ... well there are probably hundreds of tech stocks that have a better chance of doubling over the net 24 months. But I don't think money invested in NATI is a waste. Probably a good 50% return over the next 2 years.