Honestly, there is too much importance put on the racial passives. It's a massive handicap if you try to make a magic race into a stam toon...true...but generally there's not a massive difference from stam to stam race once all is said and done.

Part of this is owing to the CP system. You'll end up spending points to overcome a character's weaknesses, which will inevitably bring them closer together. Khajiit get more health recovery than Bosmer...so a Bosmer would probably spend more in health recovery in the CP tree, bringing him closer to the Khajiit.

But let's analyze without CPs in consideration. The difference in these two races are:
1.khajiit +20% health recovery in exchange for -11% stam recovery
2. Khajiit +8% weapon critical in exchange for -6% max stam and some poison/disease resist

One difference almost exactly equally wipes itself out - the stam recovery vs critical. The Khajiit buff should increase his overall dps by ~4%. The Bosmer loses out on this, but gets the recovery. But here's the thing, a gold jewelry enchant for weapon damage or stam recovery is very close to boosting dps by 4% or recovery by 11%. So put a Khajiit in a recovery glyph and a Bosmer in a damage glyph and now they're almost exactly the same. (Granted, for max builds the Khajiit will always be capable of a little more damage, and the Bosmer more recovery). But for 99% of players, either race will exist in a range where there's not much notable difference because of these passives.

So then we get to the health recovery and max stam, and honestly both are great perks that are hard to get anywhere else without huge sacrifices. The health recovery is going to help the Khajiit survive...the stam helps the Bosmer hit a little harder. There is so much varied content in the game that which is better fluctuates from situation to situation.

The bottom line is that either race should perform well for what you want. Their sneak radius is ridiculously tiny, and they hit hard as heck. Stam classes have all struggled over the past year in end game trials, but update 14 looks like a step in the right direction...and I don't see anything that makes a race inherently superior for that content. Play whichever looks cooler to you, they're both great choices.