I soloed in 25 in a Grob 103 mk1 taildragger, and I have to say, it set me in great stead, Ive since flown from the wooden ES52 Kookaburra and ES60 Boomerang to Nimbus 4DM and ASH25 &30,
With no difficulty. I later found ASK21 and Blanik particularly easy, with the Puchatek,
IS28B2, DG1000 and Duo discus close behind, all of them easier than the 103 Mk1, infact the only one as bad was the Janus B.
They were known as the concrete swan. The 103 Mk2 with nose wheel was much easier to fly.
I think the person is much more relevant than the glider, and that learning in a more difficult aircraft pays benefits later