My DD8's experience with a G/T pull-out was a giant disappointment. We yanked her out of school and homeschooled for K (when it quickly became apparent that the school's plan was "do nothing until next year"), then sent her back to school for 1st and the first couple months of 2nd, during which time she had access to a daily pull-out of more than an hour (nearly 2 hours in 2nd, actually). We were told that the pull-outs would effectively replace her homeroom language arts/math components.
The irony is that the school adamantly refused to skip her a year ahead, partially on the basis of fear of gaps. When it was firmly established that the solution was a mess, and the school and district had no intention of doing any better, we began homeschooling again, and DW is currently identifying and addressing all the gaps that the school's ill-conceived mishmash solution created.
- DD was the only 1st grader in the G/T pull-out for 1st grade, and no differentiation took place. DD was instructed (or not, depending on how you look at it) at the level of the rest of the class, which consisted of one 2nd grader and half a dozen 3rd graders.
- The work in GT was often best categorized as "enrichment" rather than the kind of serious LA/math work we were told would be taking place, and which we were assured would be happening one grade level above normal.
- No effort was made to coordinate the schedule for DD's homeroom and pull-out activities. As a result, she did LA/math all day, and missed out on science, social studies, art, and PE.
- As you can tell from previous items in this list, part of DD's day was spent in activities that were over her head and not adequately explained, the rest in activities that were significantly beneath her, creating a situation where she felt like a total outcast in both environments. Her self-confidence cratered.
DD did do a play in 1st grade with her GT class, and everyone had a part (most had multiple parts, actually). They didn't just read it, they performed it. If I were in your situation, in which I was already homeschooling, the G/T class were an option, and the program was correctly advertised as enrichment, I wouldn't have any problem with sending my DD to this class, since DW would be available to ensure that the rest of her school day was still meaningful and productive.
So, yes and no. We were HIGHLY disappointed, but if this same option were offered to your DS, you'd probably find it an acceptable and significant upgrade over what he's offered today.
It's actually possible DD will return to school in 4th grade, because:
1) The GT program separates grades 1-3 and 4-6 at her school, and the 4-6 group gets half the day in GT. This should mean that what the school originally promised DD actually happens in GT, where it's real LA/math work, and not just enrichment.
2) We are effecting the grade skip the school/district refused to do via homeschooling, as that's the grade level we enrolled her in. She'll have iron-clad results to back this up, as we're arranging for her to take the state's assessment test they give all 3rd graders.