The difference is something like $150 and the times similar (usually cheaper flights have impossible hours).

Not so long time ago I would have chosen KLM without blinking and I would have been glad of such a saving.

But now the context is different:

1. I am an SE and I am accruing points so by AC it would mean like 4,000 + 4,000 miles (I could not find the exact miles for this airport but I compared with other airports in Europe and please correct me if I am wrong and it is not 4K miles). From Frankfurt I would travel to other city by LH and I do not know whether I will get any points, let’s say I won’t.
I calculated $1 = 33.33 miles (tried to book a flight on Aeroplan and this would have cost me to purchase the difference).

So this 8,000 miles would be like $240, apparently I got the difference here.

2. I have upgrade certificates so I could upgrade to/from Europe, even if I am told that so many SEs board at YYZ, the chances to upgrade are very slim as for sure there will be someone more eligible in front of me.

Therefore, I am quite inclined to go with AC that is against all what I have done until now when travelling (i.e. pay more) so it feels very unnatural.

Is there any flaw in my rationing ? Perhaps I am missing out on something.

Thank you