The last time I wrote on this topic, I said that I am almost submerged by Tibetan Buddhism. Since then I have realised that no matter Zen or Tibetan Buddhism, the clear mind is the same whether practising Zen meditation or Tibetan Mahamudra. And investigating the emptiness of the "I" is the same in both practices. So, it does not bother me anymore what label you put it - Zen or Tibetan Buddhism. It is only the outer appearance that seems different. But I do agree for common lay persons, practising the tantric cakras and bindus (the flow of the bodily energy and blood) can be difficult even for advanced Buddhists. But almost everyone can rest their mind in simple mahamudra as well as doing zazen or shinkantaza. I find that foundation practices in Tibetan Buddhism and Lam Rim realisations gained can be valuable ingredients of any meditation practoice but it is generally not incororated into the Zen practice. However, some Zen schools may have bowing practices, so you can consider that as a sort of "preliminary practice" too.
So, it's really your own choice. There is no such thing is "which one is the best?" A best choice for one person may not be the best choice for another. That's because the types of delusions, karma and affinities the persons have are different. If you are the type of person that likes names and forms (i.e. rituals, multitudes of deities, etc), then perhaps Tibetan Buddhism will be suitable for you. However, if you are not so keen about names and forms and prefer simplicity, then perhaps Zen. If you prefer something in between, then perhaps Theravada or Pure Land Buddhism. So, Buddhism offers a whole range of methods and ways of practice to suit different types of personality and karma. It is not a "one suit fits all" approach. There is sure to be something suitable for each and everyone. But at the very root of this diversity, the core message is the same. You only need to walk it.
So, it's really your own choice. There is no such thing is "which one is the best?" A best choice for one person may not be the best choice for another. That's because the types of delusions, karma and affinities the persons have are different. If you are the type of person that likes names and forms (i.e. rituals, multitudes of deities, etc), then perhaps Tibetan Buddhism will be suitable for you. However, if you are not so keen about names and forms and prefer simplicity, then perhaps Zen. If you prefer something in between, then perhaps Theravada or Pure Land Buddhism. So, Buddhism offers a whole range of methods and ways of practice to suit different types of personality and karma. It is not a "one suit fits all" approach. There is sure to be something suitable for each and everyone. But at the very root of this diversity, the core message is the same. You only need to walk it.
This might be the last write-up before I take a rest for a while. Be well and take care! (note: I am back and I have amended a few things today - 5 Sept 2011)