When new ones come out, the hoopla is normally on the upper tier mobos, here the "Z" 97s as there's not a whole lot to really look at on the lower tier mobos, they don't really OC, most have limited DRAM compatibility, etc. There will prob be something in the near future of a round up type of thing, bey even then those are more feature oriented or this uses a brand X controller and that uses brand B
The 97 Plus does not have a sata express while the 97 Pro does. Both have an M2 socket. Both have only one 16x PCIe slot and one that runs at only 4x.
I would get the Pro board if you were picking between the two. The sata express might be nice to have for future upgrades when devices soon come out that take advantage of the faster than sata3 speeds.
I have almost 100GB of storage data that I backup regularly and I am really interested in the new sata express. Backups will be a lot faster for me with the new sata express, I believe. Currently, I backup everything twice on two different HDDs thru an e-sata port. This has saved me a few times.
H97-PRO has the same number of USB and Sata ports etc. as the Z97-A for example. The only major differences as others mentioned would be the OC'ing and DRAM. Z97-A has some minor additional features that the H97-PRO doesn't.
The H97-PRO is not available in North America. This is the board that I really wanted so now I have to decide to whether to step down to a lower Asus H97 and lose some features or step up to the Z97-A and keep the same features but not use the overclocking features. My processor will be i3-4360.
Actually I've already made up my mind and ordered Asus H97 Plus. The aforementioned CPU is supported and the mobo has all the features I require. I really don't need anything more than what it has to offer.