I had a IS250, in a manual and my 2C
Its a very poor box and had I known I would have got something else.
so this begs the question, what is a poor manual? well for me its sluggish and unresponsive gear changes.. the car itself was fine... actually too fine as I found it too sedate and sold it after about a year and a half or so for a Merc CL55 AMG, I wanted something a bit exciting and the Merc delivered, for about a month and I found it a money pit so the dealer arrived on my work place and gave my cash back and having been sick of German cars I got a rather unusual car that I actually eyed up before I purchased the Lexus, a 3 litre Subaru SpecB with a manual, but its a different kettle of fish to the Lexus, both the car and the gearbox - it has the same 6 speed box as the STi and it a more driver oriented car - I approve, the wife not so much
So, to answer your question as no 2 people are alike - the Lexus i250 manual works, but its not a great drive, for me anyway.
The car itself is fine, just check the service - its the same with any car, I had zero issues with my car, Its a Lexus after all