i agree mwid....i live in tropic region with good climate. A tree grow from seed need about 2 years to be 1.5" in open ground and about 5 years in planting media, thats too slow...a waist of time i prefared cuting instead.
hm.. I wonder wether you should be working on bonsai if you think that is too slow. A good bonsai takes time. Rushing it by taking [big] cuttings is not going to create true beauties but may give you a heaad-start. Smaller cuttings will help a lot, as seedling mortality may be extremely high in some cases. But then you only win a year or so.
I am working on a lot of seedlings, and seedling/small cutting grown maturer material. And that is great fun. It is not just teh end result., See the journey as part of the challenge and excitement..