I would agree that every gifted program is different. In our experience, the "title" of a class can tell you very little about the actual challenge level as compared with a regular grade-leveled class. Also, every single school will be different - a challenging second grade program at one school may actually be harder than an easy third grade program at another school.
Following this thread, also. Facing possible single-subject acceleration of one DYS this year and double acceleration in one subject for another DYS. Grade skips might actually be easier, but because of programming at our particular schools, subject acceleration may not be a bad place to start.
I would also agree with trying to meet the child's needs now, with possible need for future modification. Even if our one DYS has a single subject acceleration now, we expect he will need more in the future...but not necessarily all at once, KWIM? He will be quite a bit younger in the class he will be placed in, so a single subject skip alone will present some unique challenges.