I was bored, so I did build a little script to check missing votes.
It is by far from perfect.
I wouldn't even say it is finished.
But it is good for 10 minutes of fun;)

What It Does

Get all transfers to the bidbot. Look into the memo for a permlink
Get all votes from bidbot, remove that permlink from the list
What's leftover?
Print percentage of "missed votes" for bot

What It Does Not

Counting refunded money.
Yes, sent back money will not be counted and is a missed vote.
Not sure, how to handle this right now, still investigating.
Work in progress

This is the data from the last 7 days:
I guess @nettybot isn't running anymore.
And @yourwhale seems to be a scam.

Bot	"Missed Votes"
@adriatik	2 %
@aksdwi	6 %
@allaz	5 %
@appreciator	6 %
@bearwards	11 %
@bid4joy	5 %
@boomerang	12 %
@booster	29 %
@boostme	0 %
@buildawhale	14 %
@discordia	8 %
@hellowhale	5 %
@ipromote	14 %
@jerrybanfield	10 %
@kittybot	5 %
@levitation	3 %
@lovejuice	6 %
@mercurybot	7 %
@microbot	10 %
@minnowhelper	7 %
@minnowvotes	7 %
@moneymatchgaming	3 %
@mrswhale	4 %
@msp-bidbot	6 %
@nado.bot	5 %
@nanobot	6 %
@nettybot	100 %
@postpromoter	6 %
@pushup	6 %
@redlambo	7 %
@seakraken	4 %
@shares	7 %
@sleeplesswhale	8 %
@smartsteem	13 %
@sneaky-ninja	8 %
@steembloggers	4 %
@steemdiffuser	1 %
@upgoater	4 %
@upme	13 %
@upmewhale	7 %
@upmyvote	14 %
@upyou	5 %
@votebuster	7 %
@voter	3 %
@voterunner	4 %
@yourwhale	61 %