The main thing one needs to know about the Lexus ES350 is that it isn't intended to be an enthusiast car. The average age of Lexus buyers is in their mid- to late-50s, and while there are certainly enthusiasts in that age bracket, the vast majority of Lexus ES350 buyers are looking for cars that are comfortable, dependable, and possess the amenities of a luxury car without the full-boat luxury price.
While most self-respecting car enthusiasts avoid Lexus vehicles for a lack of driver involvement, I actually enjoy time behind the wheel of a Lexus from time to time. If you're just looking for a quiet, comfortable way to commute, it's difficult to fault the Lexus approach. Stretches of road that can be painful in a BMW (thanks to the run-flat tires and sportier suspension) are almost soothing in a Lexus, and the ES350 is a reasonably affordable way to enjoy a true luxury car if you're careful with your optional equipment.
Like Phil, I prefer cars that are a lot more involving than the Lexus ES350. Still, there's no denying the fact that this is an extremely smooth and comfortable vehicle. I'd rather have an Infiniti M or a Mercedes-Benz C-class since the Lexus's steering is so light and the handling so soft, but that's what most Lexus owners want, and that's what the ES350 gives them---for a reasonable starting price of $36,050. And almost any driver, myself included, would be content with the ES350's ability to blow by traffic when the mood hits, although torque steer can be an issue at lower speeds.
No, this isn't billed as a sport sedan (want one? Lexus will be glad to sell you an IS), but the ES is almost as comfortable a cruiser as the company's flagship LS. The suspension tuning is supple but never flaccid, the cabin is remarkably well insulated, and the seats -- especially when trimmed in this upgraded leather -- are as stylish and posh as an Eames chaise.