Starwood Preferred Guest - Starpoint and Manhattan hotel

You can get a free night at a Manhattan Category 4 hotel for 10,000 point which I think is a pretty good deal since dollar rate is like $350-400 for these hotels. Is there a catch, any restrictions or limitations? In other words will I be able to call and make a reservation for any weekend night in Sep-Oct?

Yes. There are no, or shall I say few restrictions, on the useage of *points.
If there is a room available, it's yours. You can make the reservation online.

FYI, my favorite Starwood property in Manhattan is the Sheraton Russell. ;)

I think is a pretty good deal since dollar rate is like $350-400 for these hotels.

Yep. And very much related to that...be aware that Starwood Lurker recently gave us a rather strong hint that we are very likely to see the Category ratings of most all the New York Starwoods jump up with the annual Category re-evaluation that usually goes into effect around the first of the year.

So if you've got any future plans for Award Stays in New York City, it might behoove you to consider booking them well before the end of the year, in order to lock in the current lower award costs.

Categories are evaluated each year based on the prior year's revenue. As this is a record-setting year in hotel occupancies and, hence, high rates, it stands to reason that many of the cat 4 properties will probably jump to cat 5.

The $300+ rates you are seeing on weekends at a hotel as basic as the Sheraton NY & Towers is testament to the very busy Fall that is ahead of us. So, now it is a good use of starpoints. At prior rates of $179, $199, etc, I would not have wasted the points.