Effective training techniques

[2LeftCleats]

Does anyone have any thoughts about the cost-effectiveness of training techniques beyond those related to heart-rate monitoring? Though not a competitive cyclist, I really enjoy riding and want to keep improving my cycling fitness and efficiency. I've looked at various power meters, which look great but terribly expensive. I know there are some cheaper devices that use indirect measurements, but don't know how worthwhile they are. Although not a measuring device, Power Cranks look like a really interesting and possibly effective training tool, though also quite expensive. I suppose I can rationalize that if I own a Serotta, a few bucks more isn't going to kill me. I'm interested in imput from folks who've tried any of these. Thanks.

[coylifut]

...recently and he's way old school. Everyone's improved by leaps and bounds. The only thing he has us using our HRMs are on easy days to make sure we're going easy enough. When not racing, we do one day of "up-tempo," one day of longish intervals like climbing repeats, or bridging repeats and one day of short fast intervals. 2 days are recovery rides and one day is a long day at low intensity.

[Trouble]

Everything I've been reading lately is so geared towards endurance and aerobic base style training, with the once maybe twice a week tempo and interval ride.
Not sure much is needed to do this type of riding/training other than the HRM monitor to make sure you're taking it easy.
This morning I rode at 70% for 1.5 hours and it was hard to stay down that low. My average mph were only 1.5 lower than my normal 2 hour hammer and I feel 100% better.
I wouldn't mind some power meter device to show me how spastically screwed up my left leg is during my pedal stroke. I try and do a lot of one legged drills on the trainer.
It is getting much better than 2 years ago though. Anyway power meter might/would teach me a smoother stroke.
Is any of this making sense???