Yes, I have flown both the Rotax 912ULS and the 0-233 Lycoming models.
The Brumby is, above all its'other attributes - easy to access, really roomy,with good adjustable seats making for a good outside view. It has a strong undercarriage and rolls over rough grass with less rumble than a C182. The Brumby has quite a high wing - about the same as a C172. The ample keel surfaces create good airborne pendulum stability. The large rudder allows for plenty of control in crosswinds.
Both engines give a brisk acceleration in the nil flap configuration - but I think a 12-15 degree take-off flap position would improve the ground run component. I did a few go-rounds from touchdown, and with full flap we were up and away in a very short distance. I think with more testing the POH might reflect my findings with flap use.
Climb was good with both engines, perhaps the Lycoming was a tad better. Anyway, we saw 700-800 fpm at 80KIAS and you'd be happy with that in a trainer.
The Brumby's sloping away nose needs watching in the cruise setup. Sitting up a little higher made it easy for me, but height challenged might need some seat adjustment. It tends to continue the climb unless you hold it level referencing the altimeter. The claimed 110 KTAS looks realistic at altitudes over 5000, but at lower levels, and 65% power settings it looked more like 105 KTAS. The Lycoming unit that I flew was several kts, (5-6?) faster than the Rotax, but then you need to consider the fuel consumption. They'll vary a lot as some will have large tyres, and be heavier than others.
The Rotax should burn about 18 LPH, while the 0-233 Lyco will likely burn 20-22 LPH. When they get one fitted with a Rotax 912iS driving a new composite 3-blade ground adjustable Sensenich - expect about 15-16 LPH.... if we can believe the advertising!
The Brumby has a nice positive feel in flight - rods instead of cables? It felt more like a mid weight C172 than its' competitor the Jabiru or a C152. It stalls benignly, and can turn on the proverbial penny if you keep the speed back in the 60's with some flap out. Now I'm a long time low level trainer, and although I didn't manage to try this in the Brumby, I'm thinking that it will be very manageable for this type of operation. Might need a bit more air venting capacity - but that's it.
I found it a very easy aircraft to decelerate and retrim with the nicely located Cessna type wheel on the top of the centre console. Holding a 60 KIAS approach down final left me plenty for the flare. It doesn't need much power to hold a 500 fpm approach using full flap. It has a nice stable feel on final and no doubt it will do a very short landing if pulled back to around 50 KIAS.
The mentioned empty weight of 345 kgs applies to the Rotax ULS, and the Lycoming is about 25 kg heavier. But, many new owners are stuffing them full with autopilots and whatever other gadgetry appeals - leaving only about 225 kg of available load. Full tanks of 140L is 100kg, so it only leaves room for a couple of jockeys! For most local flying you are never going to need 7 hrs endurance, so there is hope for heavier people. If the Rotax 912iS delivers on its' promise of 15-16 LPH, then there'll be little need for filling that 140L. There's no other way to keep the EW down because everyone wants the airframe and undercarriage to remain the way it is - strong!
Now there's been a lot of talk about the high wing Brumby being more stable in cruise, and able to handle turbulence better than its' competitors. Well, it is quite stable, but perhaps this is due to it's height from wing to wheel giving a stronger 'pendulum' damping. However, based on it's stalling speed of sub 45 KIAS - the Va for the aircraft is likely to be no more than about 85-90 KIAS - ie, approx 2x the Vs. This means it's going to be well above Va in normal cruise, and I'm interested in this aspect because we all bash through a lot of rough air in our LSA types.
That's just a few impressions, and I trust they're helpful. Do I think it will be a good trainer - definitely, it's strong, roomy and performs. As a private aircraft, with a new 912iS fitted it will be as capable as most 172's where the rear seat is rarely used.