Out of those two I would go with the SPEED. If you want to go nova I would reccomend the plus 21-5k or the plus 21-4. I have had great luck with the plus 21-5 and 5k line. For the price right now you can't beat them. the 5k sells on amain for $270, thats a killer deal on a $335 motor. And imo it is more motor than the new plus 4. Also consider the JX 21 ninja. it is basically a speed with almost identical performance at a $300 price tag.