Well, I re-strung the guitar last night, and IMO, it significantly improved things both playability-wise, and sound-wise. The playing feel is nice and taut. As for the sound - it was late when I finished up (almost 9:30 PM), but I spent about 20 minutes before bedtime, playing the Jag, to help break in the strings. I received a few pleasant surprises:
1. Sustain was improved markedly. It still doesn't sustain like a Tele or a Les Paul, but it almost hangs with a Strat in this department.
2. As would be expected with heavier strings, the note attack is a bit punchier.
3. Sonically, the guitar has more beef to it. The brightness has noticeably lessened, and the bass response has increased. It's not humbucker or even P90 beef, but (to me at least) it sounds gutsier than a Strat. As a result, clean sounds are warmer (the twang is still there - but it's not overpowering), and jacking up the gain, elicits nice sounding crunch and metallic grind. The Thinline Jag's a great punk rock tone machine. It sounded killer playing "Teenage Kicks" by the Undertones (which was the first tune I played on it). Can it do metal tones? Possibly, but extreme (as in death) metal tones may be a bit on the iffy side.
But, one pleasant discovery, was the way this guitar takes to alternative heavy rock, and grunge guitar tones like a duck to water - lots of that gnarly, single coil, metallic tone in spades! Hellooo tunes by Tad! Any body game for playing "Jinx"?
I think I'll stick with the stock pickups for now. I'm surprised that the string change made such an improvement. I've never had that happen before. I'm not sure if it's due to just an increase in string size, and/or the change from my usual nickel-steel strings (D'Addario EXL) to a steel alloy string (no nickel - D'Addario Prosteels). I wish it hadn't been so late last night, I would have spent more time playing, but the 4:45 AM wake up time for work, put a damper on playing much longer.
If I have time this weekend, I'll try to do some clips of the guitar in action (let me know if you have any requests), and post them.