Hi
The difference bewteen those 2 configs is:
With the first setup, you use a 20Gig conection between the 2 members because u bundled the 2 10G links in 1 irf-port. And if 1 link fails You still run on 10Gig.
The second setup you made is a ring topology. Your stack has 2 seperated links of 10Gig to the other switch. So you will never reach 20Gig through 1 link. But has the same redundency as setup 1, if one fails the other link is still active.
So the only difference is the amount of bandwith that passes trough the irf links. setup1: 20G setup2: 10G per link
I prefer the first setup, it has the same redundency but with a higher bandwith.
Note: This only works with a stack of 2 switches.
I hope this made sense :)
Kind regards