Sounds like a variation on "analysis paralysis".

The only downsides to a big rehab are: 1. larger variation of unknowns which is reduced with experience and 2. it may take a few weeks or a month longer, which may seem important when trying to get a unit on market quickly, but in the long run it's irrelevant.

I know there will be a little variation based on size and condition, but I wanted to see if there was some expected industry standard.

@Elizabeth C. if you're looking at cap rates you're looking at some variation of the 50% rule.

I don't worry too much about die lots for rentals, if there is a variation in the color, it has always been slight enough, in my experience that you won't notice it unless you are looking for it.

One off and variations can be challanging.  

In the kitchens I always install granite, new under mount sink and faucet, and tumbled marble backsplash, I install stainless steel appliances only if the current appliances are not in good shape / ugly.Countertops - I agree with upgrading to granite, but would suggest a lighter color with more variation, I use giallo ornamental.

@John Teachout,I'd propose a variation what Lloyd suggested:Lease to the parents and let them sub-lease to the kids.

There are many variations ranging from inheritance to lottery.

@Elisa Adam, I spent a lot of time looking for that too (slight variation).