I (and a few other people) were almost banned the last time this subject came up...so I really hope that you know what you just started Dack.
My current obstacle to doing it is money - dont have the cash for a full conversion. When I do though, ill probably end up doing something along the lines of a 1M style conversion for the handling benefits - as im already there on power.
Those renderings that Artemis posted really want to make me do it. Saw them last year (and Sibals before the 1M was even officially announced)
Im of the opinion that the 1er looks its best sans roof - a 1M vert would just be a ridiculously badass thing.