Yes, I think it would be an upgrade in ease of use, tone and reliability. For my money, Behringer and Hartke are 2 of the worst popular brands in this industry. That said, we're all different and that's ok. If you love what you can get out of that rack now and would miss it if it was gone, don't change anything. If the improved portability and footprint issues outweigh that, you could cover a good bit of the cost of the Rumble by selling what's pictured.
I use a Fender Rumble for my loudest band and it does the job surprisingly well. The tone might not be inspiring on its own, but playing around with the EQ character buttons and the EQ knobs will most likely get you to a tone that works for what you do. To get the right sound for me, I always have a Tech 21 preamp in the FX loop and the Fender's EQ section set pretty much flat. YMMV
I use a Fender Rumble for my loudest band and it does the job surprisingly well. The tone might not be inspiring on its own, but playing around with the EQ character buttons and the EQ knobs will most likely get you to a tone that works for what you do. To get the right sound for me, I always have a Tech 21 preamp in the FX loop and the Fender's EQ section set pretty much flat. YMMV