The Lenovo Ideapad series, which is consumer-oriented, did have at one point pre-installed spyware compromising all https connections. And yes the level of imbecility involved in including something that broken was bewildering. The Thinkpad line being enterprise-oriented is sparred that kind of issues, but this remains a strike against Lenovo.

That being said the only things keeping me in the Thinkpad camp are the battery life (that's truly liberating, although a competitor will probably catch up with them) and the trackpoint (on that front no other brand comes close, and none seem interested in closing that gap). But my experience with the X260 is so bad (keyboard leaving marks on the screen, screen bezel leaving marks on the palm-rest, picking up the laptop by the bottom left corner may disconnect the underlying HDD and crash the machine -- a defect known since the X240!) that I will probably forego Lenovo entirely in the future.

Dell XPS do have good press, but I've had multiple bad experiences with Dell across several generations, so much so that we taunt colleagues still stuck with that brand at the office ("so I see you've brought your hair-dryer today!").

Thank you for reply.

It's clear now. Your explanation eases my worries. I will looking forward for its security issue. I have googled that that issue can't be detected and removed.

Like what you said, I read someone has same experience when he's using Dell XPS.