Having experience with both, the Taylor has a much nicer neck - I'm not typically a Taylor fan, and they charge too much for what they are, but in spite of the bolt-on nature of the neck, they are extremely playable necks.
The Taylor is gonna sound bright - I find their tone concentrated in lower mids and treble. The Seagull is not a poorly constructed guitar, by any means, but will not sound as lively as the Taylor - they sound clunky by comparison to my ears...like a guitar with softer wood and too much glue. You could liven up the Seagull by putting some Elixirs on it, or tame the Taylor by going to something warmer like Martin or Ernie Ball strings. Seagulls get a lot of press from happy owners. YMMV, but I've never played one that I would buy. I have a Taylor DN3 - it sounds bigger than the one you're considering (dred) and it has a wider string spacing, which suits me more - between those two, I'd go with the Taylor, but I wouldn't rule out other options - a Larrivee is much more guitar in that price range than either, IMHO.