If Vespera is smaller than Stellina, do I lose quality?
Vespera's aperture and resolution are indeed smaller than Stellina's but you'd be amazed to see what you can get with a 50mm apochromatic quadruplet! Just have a look at the results of the RedCat refractor, whose refractor alone (no frame, tripod, or onboard computer) costs $750.
You can find a sample of pictures taken by Vespera:
The Moon M31 - Andromeda Galaxy M27 - Dumbbell Nebula