Sadly I have the dubious pleasure of using this junction both to and (heading in the other direction) from work as I work just over the squinty bridge. I utterly hate it and during the winter I actually drive on the back roads all the way up to Great Western Road and go on there rather than join at this shitty part which is even crazier in the dark in rush hour.
It would be OK if folk followed the lines of the road and didn't have to shove their way on or off the motorway before the solid white lines have even stopped. This just forces the traffic on the inside lane of the existing M8 to slow down drastically when the road is busy - thus encouraging folk to stay in the outside lane, then try to cut across into the off lane before they run out of space.
Something needs to be done about the layout of the M8 as it goes through the city centre. Apart from this under pass section, it is madness having an on and off ramp from the outside of the motorway. Can't think of any other motorway in the UK that I've driven who has a similar arrangement.