I'd say it depends on the perks your shadow price has and your secondaries.
The vendor shadow price is kinda shit as far as perks go (I'm ranking up new monarchy for their version). I use my ice breaker A LOT, but I have a pretty decent legendary pulse rifle (super pox VL0 from vanguard vendor, the perks are actually decent), so I'm not missing much by swapping. I also like red death, so there is that. I actually don't like the first perk on suros (slower RoF but more damage). Also, with raid primaries having elemental damage, they become more useful (VoC is a beast now I hear). With Icebreaker, gjallarhorn or any other game changing exotic, using a legendary primary that is almost or flat equal to suros seems like a no brainer to me*.
*This is in PvE