Lynn,
             I presume you have managed to get your tongue out of your cheek??  All the same, as usual I can see your argument, which is very sound as I wince every time I lift the turbo – heavy.,  However all respondents have not included my reason for a turbo besides HP.  That is noise reduction.   To repeat I measured my exhaust beside the fuse on my Glastar at 2800 RPM and 95 DB.  It really gets “excited” at over 5000 RPM.  – did not bother to measure.  Nearly all turbo blokes admit that beside the turbo I will also need a muffler to really get a comfortable noise.  The evidence will be when I actually get a noise out of my mods.
                Second point Lynn – I bent to your experience and modified the water pipe outlet with a restriction of 11/ 16 of an inch.  Just could not go with your 5/8!!    Measured all the stock restrictions  ( thermostat, housing, etc) and decided that you are right as usual that a full open pipe is not a copy of the factory design.   Again I await the results.  Day jobs keep getting in the way. 
 
 
We don't need no stinking turbos.....when we can have 250HP bridge ports......