Like I said, unless if cost is one of the main concerned here, the cons are more than the pros in modding a BMW with a non-BMW engine.
As of what whether I have driven any of the said engines, well, my old ass has owned more than 20+ modded cars in my younger life.. from a TA28 and TA22 with 4AGe, an E32 with 2JZ-Gte, Datsun Cedric 280C with a RB26, a Frontera with a SR20det, and yes the classic Toyota Supra. The engine transplants stopped the moment I got hold of a stock E46 325i, even subsequently bought a E46 318i for the missus, although she has now dump the ride aside in the garage for the Golf.
Looking back, most of the mods were just crap... hard power without real oomph, just like sex without ejaculation. Try driving an E36 or E46 M3 for a month and compare that to one of your friends modded 2JZ E36 after a month and you will know what I mean. Plus, there are also just so many good stock BMWs out there, the 335i or even the new F30.
At the end of the day, if we want a Toyota engine, might as well drive a real Toyota.