I have a Stiletto Trident II and several Quickrod 100's.
I know I sound like a broken record but with the Splawns, you have to be aware of the specific year. Anything after 2012 has the more open/modern circuit, with very recent ones adding a few extra options too (new/old, B+, etc). 2007-2012 has a much darker, rolled off sound, which I really like for some things but is definitely not the best option for some types of music and is probably where the "honky mids" reputation comes from. 2005-2006 were much brighter again, similar to the 2012+ circuit but with less bass, and of course early 2005 without the gears but I haven't owned one of those (yet). They are all superb amps but they are very different sounding amps despite sharing the same "Quickrod" name.
Either way though, these are not super comparable amps other than both being high gain heads. Totally different ballpark. The Trident, despite all of the marketing materials and online conjecture, is essentially a Rectifier circuit with a few different values/switches and shipped with EL34's (but can run either 6L6 or EL34 just like any recto can). It has less bass than a recto at the same settings, but has that trademark flatness or looseness in the low end which I mostly hear when playing low overdriven palm-mute stuff where it benefits from a boost to tighten up. It does sound different from a recto obviously, but that DNA is ever present, so if you like that kind of thing it's a very cool flavor of that style. However, a British-style modded Marshall it is not.
The Splawns on the other hand, depending on the year, are much tighter and the palm mutes a bit punchier. However the voicing, I'd say on any of them, I don't think is really meant for a classic Marshall substitute. You can get by in Gear 1 with the gain down but remember without modding, with the 4-button footswitch, you can only switch between Gear 1->2 or Gear 2->3, so no jumping from Gear 1 in a "crunch" setting to Gear 3 in a "lead" setting. Depending on the year the clean channel can go from pretty decent, to basically a dirty crunch channel if it's an early one where the overdrive gain control affects both channels.
So I guess the important question is, what type of music do you intend to use it for? I love my Stiletto but if you told me you wanted to play some Whitesnake or something, I'd probably tell you to get a Splawn instead. On the other hand, the Stiletto feels a little more versatile to me, it can do a passable impression of 90s recto tones, a little bit of more mids-forward stuff if you want, throw in a boost and it can do tight modern metal, and has the far better clean channel if desired.
Or just do what I did and get one of each....
