Regarding rootstock, the most important consideration for fruit tree success is that the rootstock be appropriate for your site. A semi-dwarf fruit tree may or may not be on a rootstock adapted to your soil and drainage.  In any case, most "semi-dwarf" fruit trees can grow to 12-15 ft., still too large for easy tree care. Tree size in the 8-10 ft. range is mostly achieved by summer pruning, not by rootstock selection.

If well-adapted to the site, however, trees on semi-dwarfing rootstocks can be easier to control than a too-vigorous "standard" tree.

For information about keeping home fruit trees at manageable size, see Backyard Orchard Culture.