It's been a while since I started the shift to flexiterian diet (I didn't switch 100% vegan immediately but gradual) I already notice the benefit.
I just had my regular health checkup early this year and the result / improvement is great (considering that it is just a gradual change only over like 3 months). My triglycerides fall 45%. My LDL only drops a little bit (good thing it is not increase anymore). My HDL level remains the same, which I hope to increase through some exercise (it seems Pilates and Aerobic are good choice).
My BMI is back on normal range (I drop 5 kg since Oct 2010). It feels great that now I can use back my old pants :-)