Stationary Bikes and Power Readings

My gym has some decent stationary exercise bikes (make/model: TRUE FITNESS Z8 UPRIGHT). These bikes have readings for watts and calories expended, etc.

I'm just curious if anyone with some PM experience has used the gym bikes and what's your opinion on how these numbers translate to road riding? I'm especially interested in the readings for output in watts?

I haven't been prioritizing cycling as of late, but I was able to sustain 30 minutes at approx. 300 watts on this stationary bike. In my opinion, based on the feel of the resistance, you never get that crank arm battle that you can face on a tough climb. The stationary bike wasn't at all easy but the pedal action feels mushy compared to actual road riding. Still, are the readings at all accurate even though the "feel" is different?

Due to work comitments I use the gym bikes a lot and then do the old freeway ride at the weekends, I find that the gym bike(set on hill level 14 for 20 then 18 for 5 mins) is more constant and you can plan the ride speed knowing in 20 s the hill will finish..You never have to stand on a Gym bike The real hills never end and kill me.
when I go back to the gym the bikes seem so easy now trying level 20 and seeing how long I can stand and attack the led hills
ps my clipless never jam on the Gym bike

Okay ... so I really screwed this one up.

On this bike, the setting for difficulty reads under watts, but the actual power output isn't related to the setting at all.

Last night, I set the thing at a high difficulty and pushed for 300w according to the readout ...

300 watts sustained IS FRIGGIN HARD !!!!!

(Lesson learned: don't post numbers until I know what the heck I'm talking about ...)