I worked full time after my ds was born for two years and will be going back full time after ds2 soon. Main motivator is financial for us. I am the main earner and we need the money. Part time wasn't an option either in my job.
I think it's okay. Positives are you get the best of both worlds. After mat leave, it is so nice to be able to go to the toilet without company, drink hot tea etc. I also value being able to use my brain in a different way. You obviously get those benefits being full time or part time.
I have friends who did part time. One went to full time quite quickly as she felt she wasn't doing her role effectively and it was impacting her career progression. Others were happy for a career to stall a bit. And actually some are doing well in a part time role career wise.
Do you have a friendly boss or mentor you could discuss it with? I guess you need to figure out are you happy for your career to potentially stall? Do you work just for money or want to go further? Can you get back on with career progression easily in a couple of years? Is part time definitely going to limit you or can you manage your boss to make it clear you are still career focused? Btw I do think it's sad that part time can sometimes stall careers as we should be in a place where flexible working is the norm for men and women but in my experience people assume you switch off the career when you go part time.
It is hard to juggle everything with full time work so it can definitely be easier to be part time. Full time also means you only get the tired grumpy time with your kids in the week so need to make the most of weekends. You need to be super organised. I try and get most errands and housework done in the evenings after the ds are in bed (which makes me exhausted ) so I get family time at the weekend.
I guess what I am trying to say in my longwinded sleep deprived way, is it depends on what is most important to you, how organised you are and what the long term impacts if your decision are. Either way good luck. I know it is daunting going back to work after maternity leave but it will be fine.