I work in a pram shop and know exactly which prams you are talking about!
They are both so different!
Pros of the Graco - cheap, you won’t mind if it gets damaged, easy to fold into a small hallway/car etc.
Cons - the car seat isn’t great, the quality is questionable & it can’t be converted into a double.
The iCandy Peach 3 - this is a gorgeous pram, really high quality, it’s probably the one of the nicest we sell. You will need the carrycot though as the seat isn’t lie flat. You can get a really good car seat with these too (any brand), have you seen the Kiddy & Joie lie-flat ones so you can use them for longer as a travel system?
Cons - this has been discontinued so you won’t be able to find the second smaller carrycot & Seat you will need in the shops now, let alone in 2 years! You might find them second hand but not in the colours you need.
Carrycots can be great if approved for overnight sleeping as they can be used for daytime downstairs naps & when staying at grandparents etc. But if you and your partner are tall might not lay too long. The new ICandy Peach carrycot is huge!
Have you looked at the egg (you can use a newborn insert & it converts into a double)? The Silver Cross Wave & ICandy Orange come with both carrycot & Seat unit included & can be used in tandem mode.
Message me if you have any more questions, not trying to sell you anything, I genuinely love helping people find the right pram for them!