Adjustable dumbbells?

So, I have been pondering making a purchase of adjustable dumbbells. I’ve finally narrowed it down (Bowflex SelectTech552 versus PowerBlock Sport or Elite 50), but would appreciate some insight. I would be able to purchase the PowerBlock Sport 50 locally.

Also, do any of you own a PowerBlock set with a barbell? If so, what are your thoughts? I am wondering if a barbell would help with imbalances when doing deadlifts, overhead presses, etc..

Thank you in advance. 🙂