I never used a trainer, but I play on Xbox (and the case : don't think I can use a trainer playing on Xbox at all), but it's all up to everyone to use a trainer or not

Only one thing I wish to say to andrewgk1 :
if you have the big wish to collect as much as goldcoints as possible, it's also possible without a trainer, but to be honest, only AFTER you've your Battle Tower and it require TIME ! You runners can collect over and over again Gems, Herbs & Ores for free (but best first invest in their gear, weapon & armor!) ...
And if you really wish to have all kind of weapons & armour ... yeah, in that case a trainer is more handy I think.
My current hero has more than enough gold (ended Ego draconis with around 200 000 gold) and all the gear I wish to have I CAN buy easely, but I don't stop using my runners and always Mindread the traders, because mostly their prices are lowered after that !
To be honest, I'm starting my current hero on 11th of march 2011 and now still playing after so many hours, at least already more than 100, at least !
But yesteraday I collected my last missing Enchantment ... so now I've ALL kind of Enchantments, each from level 1 to 10

... just my Collection Mania !