Hi Luca,
I have the Celestron 6se and its a great scope. The ota is compact and the goto is pretty good. I find it a bit dim for deep sky observing but for planets and moon is pretty good. I picked my one second for a good price.
The funny thing is i find the 6se takes more space for me as i have it ready to go and setup with the tripod. The dob is pretty compact and i have it on its mount as well. The 6se will take more time to cool down outside as compared to the dob as well which maybe a factor if you are limited in viewing time outside. Most of the time i end using binos for a quick 5 min view of the sky
I can take a photo of both if you want a comparison if you want?
I guess you need to work what you see as value and what you would want to use more. The scope you are comfortable with and ok to move outside frequently is the best value
A collapsible will help with portability and the weight of the scope. If you get a dob i recommend to get a collimation tool like a laser collimation tool. Pretty easy to do.
The funny thing I thought I would only get one scope in my lifetime. How wrong i was! Wait also until you see the eyepieces out there as well. I have found you never stop being on the lookup for the next upgrade
