I'd personally take the T series over the L series. I personally have a T430 that's still kicking around. T series are business-grade laptops and tend to be more durable.

T > L, that's about it.

I’m not familiar with European pricing. But in general avoid refurbished thinkpads of that age. You’re paying twice the price for a laptop that someone wiped physically and software wise. If you’re capable of reinstalling windows and handling a paper towel then just buy a regular “used” machine from eBay or your l local facebook marketplace equivalent. There’s not really much that goes wrong with these machines, and that’s why people buy them.

That said T580 all day long. The L series are the cheaper built machines, and the 90 series in general are basically just 80 series but worse.

Just so you know, L series is the budget, while T is the flagship. Even if one might excel on paper, you may find its build quality to be lacking.

In short: I'd go with T580.