Took The Plunge

Audio interfaces have changed a lot.
Seems like no one uses PCI anymore.
It's all Lightning, Thunderbolt, or USB.
Here's a link to a comparison page:
http://compare.focusrite.com

PCI here, too.

It's true that USB-connected interfaces are vastly more popular than PCI or Firewire.
 
There is no technical reason, however, nothing that makes USB inherently superior, to compel one to choose it over alternatives. PCI, in fact, has some advantages: slightly better latency, a smaller footprint on your desk, no need to power off and on, doesn't need to compete with other devices on the same bus. Although there are few PCI products on the market, they do happen to be some of the highest-quality interfaces you can buy.
 
The big advantage of USB is that there are so many more products to choose from, at every price point and feature set. Many now support both USB and Firewire. Overall, USB interfaces win in terms of both bang:buck and cost:feature ratios.
 
For myself, I've been a Firewire user for over a decade and probably will continue that way for as long as it's a viable option. But if turns out not to be an option on my next computer, I'd have no problem going USB.

PCI is basically the same concept as Thunderbolt - a direct connection to the computer's bus rather than having to go through a layer like USB.
 
Platinum appearing to be similar to X3 is only on the surface. Platinum goes a lot deeper, runs faster, and has some features that X3 lacks. You'll love it.

Unfortunately M-Audio never did upgrade there boards to PCI-e.

 
Wish they would have. I use a PCIe to PCI adapter card and run two units on one PCIe bus. Has worked flawlessly for two years now. There's always a way when you have a need. Someday I'll be forced to upgrade, but as long as I can still get parts, I'll stay in my comfort zone. Thankfully, caps are inexpensive.

Still running PCI here. Whats happening is motherboard makers are leaving out the PCI slots due to all the other available options. I love my Echo LAyla 3G but I know I'll have to change it down the road.

57Gregy
Records and plays. I'll worry about that other stuff later.

I'm with you on that one. I am very slowly learning how things work but have not changed a heck of a lot since my Atari and 8 TRack days. I just have more stuff to play with now and it didn't cost 1/16 of what it used to cost.. Ya, and a lot is FREE! 
 
But the beauty of using a full fetured DAW is you can use it at any level you choose. You are not forced to use all those fancy frills and features. If it plays midi and I can record an audio track I'm happy.  Over time I have learned more and more about those fancy features and slowly I adopt them into my workflow.
I now could not live without the new PVR, the Pro Channel, the Audio to midi convertion and my favorite VST collection. And only Cakewalk has those features. Well Cubase is close, but I'd have to buy it, and that's $400 I'd rather spend on Hardware.