Ah, you were in my neighborhood! Lovely out, wasn't it?
Just got back from a walk through there today. The place is looking like I could make my fortune, if I had the bactine sunburn spray concession in town.... Seriously, there are lot of purple people over there who used to be glaringly, blindingly, artically white.
And so many flowers and trees blooming! Now if: people would just control their dogs (yes, having dogs on a leash is required, and that means not letting the dog wander into all the flowerbeds and dig them or roll in them on the end of a 20 ft retractable lead!); the idiot who strung a hammock between two trees over a flower bed and was laying in it reading ended up with poison ivy; and the guy who was letting his 8 year old climb up in the fir trees, breaking branches as he went, suddenly was inspired to take him to the play yard instead (there is one - a special area just for tykes), it would be idillic. Seriously, people unclear on the concept - an arboritum and botanic garden is NOT a playground or a play park. Oh, for heavens sakes!
In case you make it back over on another nice day, the churro place is hit-or-miss. A bit farther down the road is Non Viet, where they make a killer filled baguette. Which they will happily make "to go" for you for, I think, £4.50. For "sit in" - if you drink tap water with the meal, you could have two baguettes and two frozen ice creams and you'll still have change for a £20.
The frozen ice cream is a massive scoop inside of what tastes like funnel cake, with peanuts and a bit of condensed milk on the top. (It's cheap.) Or you could just go in and have frozen ice cream.
There's also a vegan place farther down GWR towards city center. Or, on Byres road, head south from GWR. Well before you get to Dumbarton Road you will come upon the University Cafe on the west side of the street. Very Good ice cream in there! (The place has been in business for over 100 years.)