Update: Masterwork drops haven't been quite as plentiful for me as they were before the patch (that could just be RNG, though). I
did get the Firewall Mortar legendary to drop yesterday, however, and it's incredible. Inscriptions on it give me 75% more combo damage, which is fantastic as it's a primer ability. If I can hit two or more enemies with the mortar, I can instantly use it again, but that effect can only trigger once every 20 seconds. Still, it's handy.
I haven't been able to acquire any other legendaries, but again, I don't necessarily
want to. I'd rather take my time and be pleasantly surprised.
Some of the inscriptions are pretty well thought out for the Colossus. A lot of them have 'Fire Rate+11%", which incentivizes the use of heavy weapons, something specific only to the Colossus. And trust me, that fire rate makes a huge difference. I'm still hopeful for the Endless Siege autocannon, but I'm happy with what I have, too.
The Storm certainly seems to be the most popular, because I'm always grouped with one or two at least every match, sometimes three. They're fantastic at being able to prime, so it's no real problems. Their inherent ability to spread status effects helps massively, too. Whenever the Storm detonated, status effects would spread
and prime nearby enemies at the same time, but I'm not 100% it does that anymore.