Depends what you want them for. Re;height - yep, they do only grow around 2.5 feet tall. and don't need staking (unless you are in a wind-tunnel ) I confess, I only grow a few sunflowers for picking and prefer more branching sunflowers (like Vanilla Ice or Italian White, with smaller flowers (although they were rubbish, this last year). MB flowers are actually quite large, considering their height. I have not grown them myself - only seen them in other people's gardens, but it's always worth experimenting with different annuals, imo,

You can't go wrong with a sunflower. They'll be fine for cutting, but the branching types, even though they're taller, will continue to put out buds and blooms while the music box types are a one bloom and done show.

Hmmm, the seed packet says branching. The website description says 40" but packet says 28-30", but they both say branching.

Dwarf Music Box Sunflower (superseeds.com)

They do branch...but with really short flower stalks in tight little leaf axils , so if you want them for cutting, you have to take a whole stem. I really don't think they are good for cutting, (unless you grow them in rows as a crop) but as a floriferous clump to anchor a border, they have a place.