Neither Rifle has: Dust cover, forward assist, or heat shielded handguards.
The DPMS Sportical has: a 1:9 twist, conventionally rifled, unlined, untreated bbl. Chamber may be correctly cut to 5.56 NATO spec, or may be tight. The carrier key may or may not be properly staked, but probably won't be. The bolt is not High Pressure Tested (HPT) & Magnetic Particle Inspected (MPI). The receiver extension, AKA buffer tube, is the weaker commercial spec. The receiver extension castle nut may be staked, but probably won't be. The included stock is DPMS economy Pardus model. No rear sight is included, and the gas block is railed. If I remember correctly the DPMS rifles ship with a USGI type aluminum mag.
M&P15 Sport has: a 1:8 twist, 5R rifled, unlined but Melonite treated bbl - this gives you near hard chrome lined bbl life without the potential for accuracy loss from the hard chroming process. Chamber will be properly cut to 5.56 NATO spec dimensions. Bolt carrier key will be properly staked. All M&P15 rifles, including the Sport use bolts that have been HPT & MPI. The receiver extension is the stronger mil spec unit, with a properly staked castle nut. The stock is a standard M4 spec unit. The gas block is a flat top upper correct F height front sight unit. A MagPul MBUS rear sight is also included. The Sport, like all M&P15 rifles, ships with a single MagPul PMag.
In short, the M&P15 Sport sells for about the same price as the DPMS Sportical; but the M&P15 Sport has vastly superior hardware and assembly.