The Seagulls that I have played have generally been well-made, good-sounding and excellent value guitars. I would, however as a guitar repairer in a previous century, agree with frustratedguitarmaker's comments above. The back and sides do, to an extent, affect the sound. Witness the endless debates here regarding mahogany vs. rosewood and other woods! A solid wood back/sides will sound different to plywood or laminated. That is taking nothing away from Seagulls though. For the price they are very good IMHO. All the Seagulls I've seen recently have had solid tops. As someone said above, it is important to check the intonation as with any factory assembed guitar, as mistakes and shortcuts can occur.
Also just to sit in the shop or wherever and play the guitar uninterrupted for a good while as the sound is a very personal thing. The most expensive is also not necessarily the best.