I did A sharn welcome on r10 two times.
First with only augment summoning augment -
https://www.youtube.com/watch?v=vyzO-DwsI0k
Then with improved augment summoning and scion of elysium -
https://www.youtube.com/watch?v=ESHLZiF2-90
I wanted to test how much more the summonings could take with all feats.
The first one went fine. Not many reapers.
The second one went a bit bad as i died. a couple of more reapers though. It did seemed like the extra feats helped. at 14:25 you can see how the horde does against a doom reaper.