Oh dear, I did not realise that I cannot edit this post after the payout.
So, ya, I did a follow up on the ROI for this particular post. Here it is:
https://steemit.com/steemit/@simply-me/negative-roi-after-using-bidbots

My further investigation into bidbots is here:
https://steemit.com/steemit/@simply-me/how-to-use-the-bidbots-wisely-to-ensure-positive-roi-for-all-it-s-all-in-your-hand-but-you-need-to-know-how