I too have a 2009 Mac Pro and this is the first Mac I've considered as a possibility for purchase. My 2009 has had almost everything internal upgraded (the CPU chips twice), all PCI slots have cards (Radeon RX580 running three large monitors, USB3.1/C card, dual SSD boot card, and eSATA card), all four drive bays are full, and there are all sorts of external drive boxes and docks connected.
Mostly I'm now attempting to figure out how much of what I currently have can be moved over to the Studio, what sort of Thunderbolt dock/hub I'm going to need to additionally purchase, etc.
Ha. Yes, thirteen years of storage upgrades tacked on... I hear you there.
I also did the RX580 upgrade a while back to keep the OS updates happy, memory upgrades along the way, but overall not a terrible amount of investment to keep it current. In relative terms, the machine seemed stupid expensive at the time I bought it, but given 13 years of use these boxes have undoubtedly been the rock star in terms of lifetime value for all of us. I almost bought a 2019 Mac Pro when they were released, but finances were tight and by the time I was ready the whole Apple Silicon train had left the station so I decided to wait.
Ordering the Studio was definitely a considered decision and I've been watching for something that would fit the needs.
I'm running three monitors off that RX580 as well, but my main constraint has been memory, so most of the early M1 machines were a hard pass. The Studio's ability to support multiple monitors and having a RAM configuration over 64GB were the two trigger points.
I'm still trying to get my head wrapped around the memory bandwidth. If I'm doing the math properly, these older Mac Pros have 20GB/s of memory bandwidth, and if that's correct the Ultra's 800GB/s is a 40x boost. Looking forward to seeing how some of my work tasks run because they are largely memory bound.
Anyway, on the storage front, I've been trying to ditch the random collection of SSDs and PCI NVME adapters in favor of a more monolithic storage solution. Most of the data I deal with is fairly "cold" so I've moved it to a Synology NAS. The 2009 Mac Pro is accessing that via the gigabit ethernet port and I/O performance is comparable to the spinning disk inside the box (but about 4x-5x slower than the various SSD solutions), but in a real use it feels almost identical. I just put a 10Gbe card in the NAS and bought a small 10Gbe switch in anticipation of the Studio's 10Gbe port, and I'm expecting the network shares will run hopefully about twice as fast as the SSDs I have in the SATA bays presently, and the machine's primary SSD will host all the "hot" files at a much faster speed than anything I'm seeing right now.
Overall, I can't wait to get this thing in.
