Ohhhh I remember this minefield - it's a nightmare and overwhelming but honestly they're all very similar with pros and cons to many, your lifestyle, preferences and needs will determine which is best for you.
We went to both John Lewis and mammas & papas for their 90 minute sessions to go through prams, car seats and furniture- with John Lewis we focused on prams and car seats. They were amazingly helpful, asked about our lifestyle if this was our first and if we knew whether we might have another child (some prams can be adapted for 2 children at a later date), size of our car boot etc. mammas & papas was very disappointing and not really helpful, on leaving John Lewis we'd zoned in on the pram we liked and for what reasons and told the mammas & papas assistant to see what they had that was similar/equivalent - they didn't seem to have anything that matched.
So our things were - needed to fold daily well as our boot isn't big, it's not tiny but not big either, needed to be light enough when folded and fold easily, the basinet is safe for overnight sleeping which comes in handy when at my parents, they can sleep without worry, and when we travel to my husbands nans it means we don't need a travel cot.
I wasn't fussed on the car seat being able to go on the pram frame as we only have a 3 door but the car seat I wanted was the one that baby can lie flat in. As a bonus it can also go on the pram frame. The bonus is, this one can be adapted for an additional child at a later date (we don't know if we'll have a second, still pregnant with our first)
We chose the UPPAbaby vista v2 with the maxi-così bubble pro 360 car seat. John Lewis also give discount codes to use after you've gone home and had a think. Mammas&papas want you to order there and then which i also didn't like.
I hope this helps, no one can choose for you as it's based on what you're needs are, we didn't know what we wanted before our John Lewis visit, that helped us identify our needs.