You need to give more information about the boat's model year, and also information about the engine, including the production year and the model.
To assess the performance, a simple comparison can be drawn by looking at the original specifications from Boston Whaler for the
minimum necessary horsepower and the
maximum allowed horsepower. Then compare the 150-HP engine to those two limits. For best performance, you probably will want to have more than the minimum horsepower.
The minimum horsepower rating is understood to be the lowest horsepower that can accelerate a lightly loaded boat onto plane. So if your intended use is to only have two adults aboard and minimal other gear, and if 150-HP is more than the minimum power needed, then the performance should meet your criterion of "okay" performance.
Typically with any Boston Whaler boat made in the last 20-years, Boston Whaler will have provided in published data, in addition to just the minimum and maximum horsepower, a detailed performance reports showing a range of data related to performance. You need to locate that information
for the particular model year 210 DAUNTLESS you are asking about.
Q3: who is the seller of this 210 DAUNTLESS?
If the seller is an authorized Boston Whaler dealer, the dealer can give you all the Boston Whaler performance data you need. And if the dealer cannot come up with that dealer, then they would not be much of a Boston Whaler dealer.
If the seller in a brokerage or non-authorized Boston Whaler dealer, they should be able to give you the Boston Whaler performance data you need, as soon as you tell them that you are a serious buyer and
must have access to that data in order to decide if you want to buy the boat.
ASIDE: Note that this website does not particularly try to catalogue and archive data about recently made Boston Whaler boats. The focus here is on boats made 20-years-ago or longer. There may be a reader who has the data you need handy and can reply with more details. But until you disclose the boat's model year and more engine details, no one can really give an assessment of the performance of the boat you might purchase.
A STAB IN THE DARK
There is a performance report for a 2020 210 DAUNTLESS posted in a
prior discussion about the performance of a 210 DAUNTLESS.