I would choose the 3510SE - or get a quote for the 4010 SE and see that difference before deciding. But I didn't want "bare bones" type tractor either - once I saw the bells & whistles, I wanted [most of] them
When I compared, some of the SE features were great, others were just "nice to have" but not something critical to have. So you could determine what features of the SE upgrade are most important to you and then buy most of those a la carte on the non-SE version. i.e. just upgrading the telescoping 3pt arms & stabilizers to the same ones on the SE isn't very much $ at all. So wouldn't make sense to pay for all the SE options if that was the ONLY one you really cared about. Mirrors, mat, tilt wheel, linked pedal, etc could be options you really want or things you wouldn't want to pay extra to get - only you can say if they have any value for how you will use the machine.