I'll be very honest with you... I love 3rd Rail Engines the best... but MTH Ps3 engines are really nice too... I'd recommend trying one out before judging MTH prematurely... I think you might be very pleased with their newer offerings...
Even Ps2 engines from 2005 are pretty darn cool! Trust me... the Ps2 20th Century streamlined Hudson is still a staple almost 20 years later, and the electronics hold up decent enough with a battery change, and you can always upgrade to ps3 later...
David