If it's any help... I used to have a bowflex ultimate and trained exclusively on it and with a bunch of dumbbells for like two years. Even prepped for a show with the bowflex.
It's a great machine and the blaze like the ultimate is good because you can go up to 400 lbs and if you check on eBay there are even hacks to get them to go up to 600 lbs.
The motion is interesting because the major resistance with the bows tends to be at end of the contraction kind of like resistance bands. With the blaze you miss out on the preacher curl attachment but side from that it's an incredibly complete piece of equipment.
I debated buying one during this quarantine for the longest time, but ended up buying some more heavy duty resistance bands... Between those and the dumbbells I can honestly say I have not had a single bad work out since I went into quarantine 4 weeks ago.
Now regarding the adjustable dumbells, I cannot recommend the bowflex selecttech dumbbells. I have owned them and they broke in less than a year. Instead I recommended powerblocks, I bought the ones that go up to 90 lbs they are awesome. A few movements are a bit tricky like pullovers but they're really great.
Hope this helps!
P.S. The bows do break mine never did but I've seen my friends' break. The company tends to be pretty good about replacing them, not sure how it is during these days though with shipping delays and what not.