My friend owned royal enfield diesel 2 years ago.so I experieced both merits and demerits of this bike .The major problem of this bike is its top speed is maximum 60-65 kmph.when we tried to apply full throttle after exceeding 65 kmph its struggling to move on post and too much vibrations on the handle bar and seat.Also the pickup of diesek bullet is very poor compared with petrol version.Another major disadvantage is its polution.Becouse of diesel engine it pull out more carbon dioxide smoke , its not good for health.It can be avoided by proper maintenance .But the maintenance can be taken after every 2 months .For an avarage person cannot affort the maintance of a bike in every 2 months.