I wanted to test out the list with 3x shardless agents and ended up going 2-2 overall. Here are the match ups:
2-0 Shardless Bug Won game 1 by out racing the opponent, I played 3 lords and just kept bashing in with them for the win (he played 2 deathrites which blocked early turns and died, and a goyf that could block enough to prevent lethal). The opponent also misplayed and used abrupt decay on vial (when i had 1 card in hand) instead of on a lord which made his blocks inefficient. Game 2 I brought in RIP which shrank his goyf and made his 2 deathrites useless. He ended up playing toxic deluge (turn after i tap out to play rip and swing with mutavault), which i was fine with because I had 3 slivers in hand still, which also cleared his board of goyfs and deathrites. He wasn't able to recover from there.
1-2 UR Delver Basically won game 1 after a mulligan to 5 with no lands (kept a cavern on top with scry), but had aether vial, gale rider, and lords, and 1 STP. Got there game 1 by drawing into lands and swinging in hard and fast. Lost game 2 which would've been a win if i just drew a galerider, numerous times i had lethal but no evasion (perhaps i should play the 1 winged sliver). Game 3 he flipped 3 delvers and killed me quite quickly.
0-2 Miracles Game 1 was a loss, really good miracles player got his monk tokens huge and swung in while keeping lots of tokens up for blocks. Game 2 i put huge pressure on the board and again just needed flying to get lethal, even after he engineer exploded 2 aether vials and nearly my library + ethersworn canonist (i brought 2 canonist in, turns out it is BAD in the match up). Here shardless shined by allowing me to recover after numerous terminus's (he played 3!!!!), but once he got his tokens going I couldn't keep up (he would chain 2 tops over and over again with 2 monks out, generating 8 tokens a turn on 4 lands).
2-1 Thoughtlash Control Game 1 i ended up milling him by just swinging in for 20ish damage for 2-3 turns in a row. G2 He ended up getting his lab maniac win con on me as i had no counter spells or STP's to deal with it. Game 3 I played harmonic sliver off of cavern on turn 3 which crushed all his tops and thoughtlashes.
Overall Impressions: I felt that 3 shardless agents felt clunky. I ran into a string of bad luck as well, often drawing into my wastelands without having targets (delver, miracles, thoughtlash), but I'm not convinced I would've liked mutavault instead in those situations. Sylvan library proved again to be an amazing card in this deck, giving me game against every deck i played with. I do believe a lot of my losses were due to side board errors, and accidentally siding out useful cards for non impact cards.