The power to weight ratio would be more than adaquate for IMAC type of flying and some 3D. Keeping the weight down wherever you can in the set up helps with any plane. It was designed around an 80 to 100cc engine, so you are already near the top of the power range.

The Lanier 300 is an older design, but flys well. It was never the lightest kit on the market anyway, so I wouldn't be concerned much about that.

Unless you are already the area 3D hottie, I doubt that you will ever note any defincies in the flight manners. One of the nice things about Brison engines is their ability to run for far longer that you will usually have a use for them, and their reliability, which is very high. Also the ability to get parts for the engine should you need to for any reason.

As far as needing to have the most current aerobat on the market, I still have an old Ace 30% Extra 230 with an old Sachs 4.2 that's pretty heavy, but still fun to fly. Because it's still fun, I wouldn't get rid of it.

My opinion is that the combination is not a bad deal at all, and will give you a good learning platform.