Fond memories of our old Layla 24/96 all the way around. That interface was really the beginning of the digital end of our business almost 15 years ago. Swapped it for an AudioFire Pre 8 about 5 years ago and it still sits in the mix room to this day, working without a hitch.
Echo always made the best drivers, even when they were writing them for Mackie products. I don't know that I would say Firewire is becoming extinct however, perhaps for the consumer end of audio interfaces but, for the pro market, there are many manufactures that still embrace the interface ( Presonus, Mackie, Steinberg, MOTU, Avid, Focusrite, Universal Audio, ect ) Your not likely to find any version of Firewire on a MOBO that will work well with most manufactures products anyway so, you will be buying a separate PCIe adapter board and those are widely available.
Laptops/Tablets are definitely all USB but if your transitioning from a Layla 24/96, It doesn't sound as if that's where your headed. While it may be possible to do multi-track audio on a phone/tablet, it's not very practical once the novelty wears off lol!!