That 26 mOhm figure is the spec to check against your load current and duty cycle.
175 °C junction — thermal headroom for high-ambient designs
The junction temperature range extends from -40 °C to 175 °C, which is the upper end for a power MOSFET. In a motor drive or PFC stage where the heatsink sits in a 70–85 °C ambient, that extra 25 °C over a 150 °C-rated part buys real margin before derating kicks in.
Gate charge and input capacitance — what the driver sees
The ±30 V maximum gate-source rating gives headroom for ringing on long gate traces.
D2PAK footprint — layout notes for the exposed tab
The D2PAK (TO-263) package has two leads plus the tab, which is the drain connection. The 0.50 mm lead pitch is typical for this package; the recommended land pattern is in the datasheet.
The HEXFET series has broad distribution, so multi-source availability is typical.