Its been the better part of 15 months since I flew one, but my experiences were nowhere near as bad as that. My technique was to maintain 290kts until I could no longer maintain 1000fpm climb. I would then VS 1000fpm until airspeed dropped near 250, then try to maintain 500fpm at or above 250kts. If I could not maintain that, I would level off and accelerate.

Climbing like that (admittedly a non-standard profile), I never had a problem getting into the mid-30s, even after a summertime MTOW departure...and it would normally accelerate to 0.74m or more after 10-15 minutes of level cruise.