FWIW, my preference is agains triples. Too much shifting up front, more likely for chain to fall off, etc. With a compact crank and mtb cassette and rear derailluer, you can have pretty low gears -- probably adequate for everything except heavily loaded touring on steep grades. OTOH, triples are so prevalent these days that you can't go all that wrong if you go that way either. Comes down to personal preference and riding style more than anything.