ZvT: Beat Mech with Swarm Host/Muta on Alterzim Blah Blah

I'm silver league, so there's absolutely room to improve this strategy, but it feels new-ish and it takes advantage of a new map's geography (Alterzim BlahBlah--the purple one with the happy naturals). So, I'm posting about it to make it a straw man for the other DayKnights. It's interesting, because I just won handily with it despite the following:

1) Terran pulled ahead by at least a dozen harvesters after a supremely effective blue flame invasion early in the game

2) Terran took a 2-3k resources lost lead over me after his first major push--tank/hellbat/thor (I think at 10-ish minutes)--killed one of my bases and most of my first army.

3) Terran had four bases while I also had four bases. That kind of means he was beating me in bases, right?

4) Terran was beating me in upgrades (as of my final push, I had 2-2 range, 0-0 air, and he had 3-2 mech)

5) Terran had significant mech infrastructure (this is meaningful, because many times in Silver, "going mech" means building two factories instead of one, so replenishment is a non-issue for Zerg)

The story is this (If stories are boring, check out the replay):

Taking 3 bases early was my top priority. Around the timing of my 3rd, I scouted mech and prepped a roach warren and 1-1 range. Hellions hit and, because I was dumb, I lost a bunch of Drones because my roaches weren't born, yet.

Anyway, on Alterzim, natural and main are both behind a skinny ramp, so I imagined swarm hosts and nydus worms would be good for both defense and siege. Lair and Infestation Pit followed.

I Nydused into his natural, because t, I planned to use it as a distraction before sending the real Nydus to the front of his main. As it turned out, though, his 1st attack was on its way to my base, so I just used the worm in the natural. Swarm Hosts killed a bunch of SCVs at the natural, and I sent one more round of locusts to his main for those SCVs before I nydused my Hosts back to my main to defend.

I put them at the top of my Main's ramp and send locusts to meet his mech army. I reinforced with roaches. A lot died, including my 3rd, but he lost some, too. He hit my third before my hosts got there, so I think that's why my losses were so high.

Anyway, skip forward and I won by sieging his main with Hosts (he found it hard to come down his own ramp with my locusts there), while I picked off expos with a big Muta cloud.

How do you guys see this strategy working or failing at higher levels? I'd love some input to fuel my practicing.