It is the counterbalance shaft that takes all the life out of it.
Just the 270 crank alone would feel like a v-twin. Perfectly fine for a crank.
Something similar might explain my baffling lack of longings for one of those new Triumph Bonnies or their other Retro offerings, 'cause I've always adored Triumphs since I was a kid. On the one hand the newish ones come very close indeed to pushing all my buttons visually, but they just seem to lack that old galloping "grunt" when I see one flit by. I like 'em and all, but they don't exactly keep me up at night plotting to get my mitts on one. I'd assumed it was just emissions gear or better metallurgy or something else twisting and muffling their balls, but the new ones really are an elementally different breed than the old ones, Huh? Well, at least I still got my old '67 Norton next up for resurrection after the Zuendapp Bella gets some love...
(http://www.bukmop.com/RoyalEnfield/NortonInShed.jpg)
The "Desert Sled" in Hibernation