Many have enlarged the stab and especially elevator, and report better control feel. Some have made it much larger, like a doodlebog, but then it doesn't look like a streak. One of the cool things about a streak is the rudder, stab and tip shapes. You could tell Mr Aldridge had training in design.
If I were to do it ( and I have a lightening streak kit on the shelf) I would increase the stab and elevator, especially the elevator chord. If you want it to still look like a streak, just add another 1/2 inch to the stab chord. The structure could use a little updating to make it easier to scratch build. The tips could be reworked to make them easier to cover and add a adjustable lead out to, but that is about all.
I would dump the sheet spar use, and use cap strips like a lightening streak, longer motor mounts. and cut down the rudder. It is about the right size for general fooling around with a 20-25 engine and it fits in the car well. I would keep the 1 wheel gear.
If you lengthen the nose, tail moment, and junk the flaps, change the tip shape of a streak you have a Sig Sky Ray. If you want something to start with and modify, the skyray is a better choice. More modern structure, longer moments and a modern control system.
They are very close. Put the plans side by side sometime.
Dave