I just realized I posted my first uses of the new C5-3s on YORF but not here. So here's what I posted there:
I flew three of the new C5-3s on the 14th. Two in a 1/200th Saturn V and one in a MAV. Both of these models are marginal off the rod on the C6-3 and go really well on Q-jet C12-4s.
All three boosts were very authoritative and with quite a visible flame from the exhaust. Altimeters aboard showed the 1/200 Saturn V actually didn't go quite as high as it does on a C6-3 (when the winds are low for a straight flight) but the MAV did about 70 feet better on the C5-3.
Both models go considerably higher on the C12-4 than they do on C6-3s.
So for heavier models that are marginal on the C6-3, it looks like the C5-3 is indeed "mission accomplished" but for C impulse competitions, the Q-Jet C12 is the hot ticket by a large margin (and even for lighter models).
After getting a comment about the altitudes, I added this:
Yeah, I was a little surprised at that myself, but at the same time, the MAV is heavy but not all that draggy (especially relative to the 1/200 Saturn V), so I would guess the momentum increase overcame the increased drag [of the higher speeds]. As others have noted, and the cert data shows, the delays are a bit over 3s (a bit unusual for Estes motors).
I will be flying more of these motors (I have six more and will be ordering a larger quantity from AC Supply soon so will be doing some more flying...and I almost always fly an altimeter aboard a model, regardless of what it is.
And then this:
The 1/200 Saturn V is a ~200 foot flight on either C6-3 or C5-3. On a Q-Jet C12-4 it's ~350 and on a Q-Jet D16-4 it's ~425.
The MAV goes a little higher on all of these, and the C5-3 (in the one flight I did) took it about halfway between where a C6-3 and a C12-4 does. I only have five flights total on the model (vs. 20 on the Saturn V) so not enough data yet for real trends.
I hope to go flying on Sunday so may put one or two more of my currently remaining six in something lighter/less draggy to see how it works there. The trick then will be not having the delay be too short, though it is, unlike most Estes delays, a little longer than the rating as I noted above.