nrad2000,

are you using a y-connector or are you using servo mixing from the rx (putting the servos on 2 and 6 channels) for the elevator servos? In the case you are using a Y-connector, it is common to have the the elevator halves deflecting at different angles for the same input and you cant correct this mechanically. With the channel mixing from the RX, I am told there is a slight difference between the time the left and right elevator servos react. This lag is because the RX reads through the channels one by one. Both of these could be causing the snap you notice at the end of the loop. For the record, I am using the rx mixing setup on all my airplanes so far without noticing this problem. But for my new Funtana, I was recommended to go for a match box (just search MSA-10 on Tower for Futaba, JR has an equivalent) so as to get rid of the lag.

With respect ti the tendancy to pull to the left in the vertical, I noticed the same problem on my Topstar which is a 3D airplane from Phoenix. I noticed that as soon as I applied throttle to enter the hover or to control altitude in the hover it would pull left. What it required was more right thrust- hence I added a couple of washers under the LHS engine mount and the next time the tendancy to drop to the left was gone. You dont notice this in straight and level because of the rudder trim that you may have. Also, I suggest you balance the model laterally if you have not already done so

Hope this helped

Ameyam