Mine is slower to start when it has not been driven for more than about a week. My best guess would be the cause is the oil from the cold-sumping getting ingested into the cylinders on first turn-over. It always starts after 20 seconds or so, runs fine, and then re-starts quickly.
Changing to a battery with higher CCA than the factory Banner makes the starter motor turn over (and the engine start) noticeably faster.
