They've exchanged a bunch of cash for cash-flowing assets.
The question isn't at that level, IMO. It's how much value is being created with your capital, how much will be created going forward, and are the assets in aggregate durable and growing, or slowly running off (return of capital, rather than return on capital). Have they shown the capacity of creating enough value in the space to be worth investing in vs all the other companies available to you on the public markets (which is the question you should ask before any investment that falls in your circle of competence).