Hi Dave
The big question is always scale or not.
Scale is pretty but can be expensive and fraught with lots of maintenance, whereas sport is ugly but much more practical.
My new Hanger 9 Decathlon is roughly the same wingspan as the 1;3.5 Wilga, but getting on for twice the wing area, and it is nearly 6kg lighter than the Wilga. The problem comes in on a breezy day like yesterday, where you are trying to land quickly and it is just too floaty. Great for small fields and light wind days but taxing near the ground. The Wilga is a much better all round proposition but Frisch does not want to deal with the UK and the Tomahawk kit is very expensive, so that leaves Colin Bonds plan which is a big build with a tricky undercarriage. And therein lies another big problem.
A good day for a glider pilot would see around 8 flights, so that's 8 landings, whereas a good day tugging might see 60 tows or more, so that's 60 landings, and landings on an over engined powerful tug make the whole plane and uc take a battering. It's usually landings in one way or another that kill planes. The Wilga uc is quite complicated and prone to failure. Pretty to watch when working well, but an early trip home when it goes wrong.
The sport planes are much more suited to the pounding that towing throws at them, but it's just whether that's your cup of tea or not.
A one third Cub on a 111 or DA100 will be very powerful until you hook up a big glider to it and all of a sudden it might seem a bit slow.
The main things to remember are that you always need to stay in front of the glider so speed can be your friend on a strong, heavy glass glider, but at the other end of the spectrum, always be prepared to use your throttle for the lightly loaded woodies.
Never overestimate the power of your tug in trying to climb too steep. A glass glider pilot will not thank you when it tip stalls and falls off the tow.
And always be willing to say that you are not happy to tow something which you think is too heavy or too light for the tug that you are using. The glider pilots will normally thank you for your consideration.
So scale or not. The choice is yours. There is no easy answer. But the easiest way to dip your tow in the water is with a sport model, especially one that has been designed for the job in hand.
Oh, and use the most powerful release servo that you can afford. Trust me, you may be relying on that one day.
Probably confusing, but nobody said it was going to be an easy choice
Ray