For the price you would pay to try those new ones I would just get an fx5 cuz you can't go wrong with one...
I have a Fluval FX5 for my 150 already.
For the money value, I can see your point, however I would prefer a smaller filter for the applications I'm planning due to space. If I found a Fluval FX5 for a good bargain, I might get another one.
To explain my plans, I'm aiming for three different medium sized canister filters right now.
One for my goldfish who are in a 55 gal, I think a Fluval FX5 might be too much current for them in this size tank. If I buy a huge canister filter, I won't be able to afford a larger tank for the goldfish until who knows later when I get a new job. If the water flow from a Fluval FX5 could be reduced enough and could fit on the stand so I could still walk by the tank and access a clothing closet, this is a possibility. Since the Fluval FX5 is rounded, I'm afraid it would stick out on the 55 gal stand and get in the way. I was trying to get a used Eheim 2260 for this tank, but I gave up on that and decided a medium sized canister would work fine for them until the upgrade happens. Maybe later when I get that planned 75 gal for them and move them into the living room.
Another one is planned for a 55 pleco community tank which is behind a bed, a more powerful filter would work out in this tank if I could use a spray bar, except wedging a large filter in there that would be difficult to remove for cleaning doesn't seem like a good idea. My other 55 pleco tank does fine with a Eheim 2217 so that's what I want for this tank.
Third plans I'm making due to my Fluval FX5 being unexpectedly dirty during my last cleaning is adding a second canister to my 150 gal. The first Fluval FX5 is next to the 150 gal on the floor, not sure where I'd put a second one since there's a 55 pleco tank on the other side.
To put a long story short, I am in a rental house that is run down and has a lot going on. I was working towards finally moving my largest tank in with me, but then a outlet stopped working in the rental house and killed a tank of killifish and pleco.
Had I moved these two tanks in the rental house, there would be plenty of space for a second Fluval FX5 in the basement. One of the issues I'm facing there is the basement sink is broken so it means hauling buckets up and down stairs and I cannot see myself doing this for a 150 gal tank so I avoid keeping fish down there despite that I have a fish room for the first time in my life.
So as you can see, I'm thinking medium sized canister filters would be the best choices for my current situation. I had set aside about $200 for when I was trying to get a used Eheim 2260 for the goldfish tank so I could buy two medium sized canister filters right now with what I have saved up so I've been shopping around for good deals and sales.