Chassis balance is one of our few complaints, as the 135i is plagued by tire-howling understeer-more so than with the 335i - a situation that's not helped by an open rear differential, a minuscule rear antiroll bar, and front tires that are narrower than those used on the rear. That said, steering feel is fantastic - it wouldn't be a stretch to say that the 135i's hydraulically assisted rack (all other 1-series cars use electrically aided steering) offers better feedback than any other current BMW, and that's saying a lot.
This is all well and good, you think, but really, why do I need one? Why shouldn't I just buy a base 3-series for about the same money - it keeps winning awards, right? - and get more trunk space, a bigger back seat, and more Joneses-wowing street cred?
Simple: with the 1-series, the appeal is in the intangibles. Indeed, the 135i isn't spec-box perfect (witness its pudgy curb weight), it isn't dynamically faultless (BMW engineers have hinted that their primary goal was ride quality, not balance at the limit), it isn't cheap, and it isn't a track junkie's dream (that would be a lighter, high-strung, four-cylinder screamer).
What it is, though, is something of a renaissance. In essence, the 135i is BMW doing what BMW does best. In spite of all the superbly engineered autobahn missiles and the quirky-but-capable sports cars, the company's forte has always been small, fast, and relatively affordable sedans. Forty years ago, the Munich carmaker built a legacy with the 1600 and the 2002; twenty years ago, it cemented that legacy with the E30-chassis 325i. In spite of what BMW's marketing department would like you to believe, the 1-series isn't a reborn 2002 - it's far too portly and thirsty for that - but it is a return to the principles that have made BMW great. The 1-series is compact, endlessly involving, and absurdly fast. It is everything that the 3-series was before that car grew up. It is also more fun than a caffeinated circus monkey.
So, break out the confetti, kids, and start warming up those checkbooks. If you hadn't guessed already, your lives are about to change.