You're more likely to find a salaried person missing a detail, or deadline, and at times they'll go on vacation without properly handling your file. Some of them are figuratively on cruise control and lack any sense of urgency. It happens all the time even though r/realestate has a hard time trusting us agents. You can find commissioned agents who are disconnected as well, but I've seen more failure rates on the salaried side though. They're just indifferent.

Your agent should be giving you their opinion of value prior to hearing what value you'd like to write on the offer. This should squash most/all concerns in terms of the conflict of interest. The difference of $550K and $575K is indeed impactful on the buyer's cash flow, but it's minimally impactful on the agent's income. For me its zero impact, you'd have to be the judge in terms of whether a $600 revenue difference is affecting your agent's advice given the client will generate ~$12K in revenue. Again though, get their advice up front prior to planning an offer. They shouldn't be shuffling their position! Along these lines, good interviewing will help you avoid someone who "needs" the revenue at all. It's always best to find a commissioned agent who is good enough at their trade to be free from needing the money. IMHO.

Personally, and I know many agents are similar, we're proud of getting a property for our clients "under list price". I don't want to give too much credit to a list price, which is a mere advertising figure, but we are balancing what price we can get for our clients to be as low as possible given the seller, market conditions and the strength of our buyer.

The moral of the story though is this: Don't get lured into making this decision based upon the compensation structure of Company A, or whether or not that company will rebate you some money. If you focus on those details, you're overlooking very important performance metrics that you should pay attention to.