Summary
Sims was drafted late in the 2nd round in 2021, going 58th overall. Considering his draft slot, he had a pretty encouraging rookie season, playing in over 500 minutes of non-garbage time across 33 games, according to Cleaning the Glass, and played even more than that in '22-'23 despite the Knicks adding a quality back-up center in Isaiah Hartenstein in 2022. However, he suffered from injuries in '23-'24 and didn't play as much.

Sims is a rim-runner, and hardly shoots anything that's not a dunk or lay-up. He has hit 80% of his shots at the rim, one of the highest rates in the league. He's a lob threat in pick-and-roll, and can finish dunks off cuts or just hanging around in the dunker spot for dump-offs. He also attacks the offensive glass well for tip-ins and put-backs. Free throw shooting could become a problem for Sims, as he has only hit 53%, which is consistent with his final year at Texas. Poor free throw shooting is also not a great sign that he could ever expand his range at all.

Sims has some really defensive potential due to his athleticism. Not only can he sky for some big blocks as a rim protector, he moves his feet pretty well on the perimeter. You wouldn't want him switching onto guards or wings often, but if he has to late in the shot he has a decent chance of holding steady. He has some nice discipline on verticality that should only improve with time and more NBA reps. 

Despite playing behind Mitchell Robinson and Hartenstein, Sims has been able to get a decent amount of playing time, even playing some power forward in two-big lineups. He has shown potential to be a high-level back-up, but his limited playoff minutes in 2024 were not great, as he seemed overwhelmed a bit, like a deer in headlights. He is also slightly older, as he will be nearly 26 years old when the '24-'25 season starts.
 
Cap Considerations
Sims has a $2.1 million team option for 2024-2025, and the Knicks may decline this option to make Sims a restricted free agent in 2024, rather than picking up the option and having Sims hit unrestricted free agency in 2025. If the Knicks decline the option, Sims will be a restricted free agent with a $2.4 million cap hold and Qualifying Offer.

However, the Knicks could refuse to tender the QO, which would make Sims an unrestricted free agent in 2024. I don't think the Knicks will feel the need to lock Sims down on a long-term deal in 2024, and would expect them to simply pick up his option.

If his option is declined, other teams will have multiple ways to sign Sims as even teams without cap space could use any of the Non-Taxpayer MLE, Room MLE, or possibly even the Taxpayer MLE or Bi-Annual Exception to sign him to an offer sheet (although you rarely ever see offer sheets below the full MLE). However, Sims being a restricted free agent will greatly lower his interest among teams, as they will worry that the only way to pry him away from New York would be to overpay him. If the Knicks don't give Sims a QO, this likely means he could be had for the minimum.