The G10 Endura weighin at around 4.5 oz., while the regular Endura comes in at around 3.6 oz. That extra ounce may have been a deciding factor for some users. For me, I try to limit my carry pieces to no more than 4.0 oz., tops.
It wouldn't be the first time Spyderco introduced a model that one would think would be popular, but turned out to be a slow seller. The original Manix (4mm thick blade, lockback) comes to mind. I'd love to have one, but they're really pricey now.
~Chris
The extra weight was due mostly to the much thicker steel liners. I had both the E4 FRN and G10 (sold the FRN) and the weight difference was negligible IMHO.
The G10 Endura was a very well made knife with a smooth and solid lock up. It sold for ~$120 street when it was available. When they closed it out they had a disco blow out special of around $70 +shipping. Those went fast.
I bought my Endura 4 G10 for $70 just before it was disco'ed. I have to say, it is one impressive knife. The fit & finish on mine is absolutely phenomenal and yes, it is buttery smooth with vault-like lockup. I EDC it on weekends and vacations since it is a tad big for an office environment.
I'm actually looking to get the Delica G10 if I can find one at a reasonable price. I'll probably snatch up the Dragonfly G10 also before they disco it (if they haven't already) or supply runs out. I really like the foliage green G10 they use on them.
Obligatory pics: