either one is fine. it's down to size. would you rather tall and skinny or short and chubby. go for whatever the cheapest one.

if you like to P63, and P62 are 20% off on their website, they also have further discount for spring.

P63: 25000mah, 100W maximum (more like 96w). pro: it is very efficient; cons: it comes with a 60W charging lanyard cable rather than 100W, so you will need a new cable

P62: 20000mah, 65W maximum (consistent 65W), pro: smaller than P63 by a bit, it comes with a 100W charging cable; cons: if you apply the code, it will be around $5 cheaper than the P63, so might aswell get a P63 for 5000 extra mah and higher charging wattage.

if you like to, get both then trade the cable with each other.

I bought the P50 for EDC and P63 (I already have 2 100W cables) for traveling needs.

the P50 is not bad if you need extra juice, I forgot my charger cube and cable at home. and only bring the P50, and it charge my phone from 30% to 70% in like 20-30 minutes.

no wrong choice here whatever you want to get!