'Birds first came onto my radar in I'm thinking somewhere around '08. At the time my main bass (actually, only bass) was my Precision. There was a music shop on the mainland I always tried to go into whenever I was off-island. I recall walking in to their bass room one day, and while they did usually have a decent selection of Epiphone and some Gibson basses (mostly SGs and Les Paul), on that day, hanging there was this big wonky shaped thing made of this incredible wood. I'd never seen any bass like it, and it was about as far removed from my Fender as I could imagine. I played it a bit, and to be perfectly honest I wasn't 100% sold on it. The string spacing was much tighter than my Precision, the neck was small and made my hand cramp up, and the frets were like railroad ties (my main issue with pretty much all modern Gibsons, and Fenders as well). But it looked incredible and smelled great (still smells great, I need to get that scent and put it in my laundry). More over, my father who was with me and is a carpenter, was blown away by the wood. He loved the way it looked too. Of course, being in 9th grade I didn't really have the cash for it. I worked hard that summer to try to save up, but still didn't have enough. But, knowing how much I wanted it, and liking it himself, my dad helped me cover the rest of the money as long as I paid him back. And that's how I got the Zebrabird.
It sort of became a case queen, really only took it out for performances/to show off because of the aforementioned issues I had with it (string spacing, small neck). I also found the pickups to be far too dark compared to the brightness and attack of the Precision, which remained #1 (and really, it still is).
Through trying a number of different basses (Jazz, Rick, EB-3), I came to realize I like simplicity in my basses, by which I mean the Precision setup of one pickup, a volume and a tone control. I'd seen Glenn Cornick play a T-bird II with the precision-esque setup, and so reading through TB and Fly Guitars started to hunt for one of those, eventually landing on the Greco II. I loved the look of the II, stripped down, back to basics without the second pickup cluttering everything up. Though I've since adapted and neck size nor string spacing bother me anymore, the Greco felt much more like home, with the wider neck, smaller frets, and larger spacing. Plus, it looks more like an original one, with all the Chrome, large headstock, etc, which I'd come to far prefer over the black hardware on the newer birds (Zebrabird included). There's a reason I have all the chrome covers on my Fenders.
At this point I find the birds just very ergonomically comfortable, keeps my right arm fairly straight as it rests across the lower fin, and it feels proportionately right (doesn't look small or overly large on me). With the pin at the neck, it also keeps the bass at roughly a 45° angle, which allows me to keep my left wrist and arm fairly straight, helping with speed. I've spent the last week almost exclusively playing the Zebrabird (it's my only bass with newish rounds on it currently, so it's the brightest), and boy does it play great. Still not 100% loving the tone, it's just a bit dark, but it has it's place and I have my other basses (once they get new strings) for my brighter sounds.