80mm is big enough
With an 80mm refractor and an eyepiece you should be easily able to see Saturn's rings - normally. However, they are currently only slightly inclined to our point of view and so less obvious.
Planets and the Moon should work well - even in Trafalgar Square - as they are so bright.
But dimmer stuff ideally needs tracking. I have seen no mention of that in the review. Also, is it goto or do you have to point the thing (something 95% of the population will fail on - even for the planets)?
Might have been better to draft in someone who had used a telescope more often to evaluate it.
And BTW the Seestar and Dwarf II smart telescopes may be a better bet and similarly priced.