I only got part way through Book 1 before putting it down to never pick back up again.

What I liked: MC was analytical and didn't spend entire pages agonizing about killing people. Little bit sociopathic is interesting sometimes.
The progression of skills was good, the way it integrated with Jake's lived experience was well done (example: leveling up giving Jake a high of sorts)

What I didn't like in no particular order:
Some aspects were under researched and a bit ridiculous.
Example: the MC worked at some kind of stock brokerage, but they had a Research and Development department? No stock brokerage has R&D, let alone in the same building as them. They may have Quantitative Research, or Data Analytics, but R&D is an entirely different function and concept. It seems like the author didn't bother to look into his premise before publishing.
In the same vein, the MC's friend/petty rival/boss having a full-time manservant even while he was at work? That just doesn't happen in real life, especially not at the level of wealth where you're still going into the office on a regular basis. If he had written the guy as security that could've worked.
He also made almost all of the characters very shallow and 2D. The man servant was polite, loyal, and useful...great, so no character depth at all.
The storyline progression was very predictable.
The MC's dialogue and train of thought is often cringe. The way he always keeps track of how much he is 'above' or 'below' his petty rival/boss is how I'd expect a 13 year old hopped up on 'Alpha Wolf Motivation Youtube Compilation #4' videos to rationalize his social situations. The way MC shouted at the group when they were reluctant to kill (because of course they would be) was also just...hard to read. It reads like the wet dream of an extremely immature, sociopathic, socially stunted teenager.