We believe Alimentation Couche-Tard is a cornerstone piece, a "Foundational" type stock and one that you can set and forget for many years. Parkland of the other hand is more of a growth company, one that is smaller in nature and expanding faster. Also, Parkland does have exposure to the refining industry, as it does operate refineries.
The two companies are very similar, but do have some differences. If you want the blue-chip nature, go for Couche-Tard. If you're looking for a company who's expected to grow a little faster, has a higher yield and a monthly payout, Parkland does present more risk, but more upside opportunity.
It is very likely that the company's refining exposure is holding it back (PKI). However, the core of its business is much the same as Couche-Tard, and it's rebounding in a big way in the US.
Because of the price action of Couche-Tard earlier in the year due to its failed acquisition attempt, I ended up taking a position in it. However, I sold it for a profit in the $46 range and now I (Dan) only own PKI, and plan to own PKI for the long term. I've owned the company for around half a decade, and have no intentions to sell.