Sorry - this is long.
I live in Canada and receive packages from the US for work all the time. The amount you pay as the sender is probably similar for both companies (just quote it on their websites), and service is fairly similar, but the amount that the recipient will be charged on delivery can vary greatly depending on what company you use and how you prepare the paperwork.
Regardless of what company you use, the recipient will probably be charged duty and tax (GST/HST/PST). On top of that is an additional processing or brokerage fee which varies by shipping company. These fees are often worse than the duty/tax (e.g. DHL charged me a $14 fee to collect $4 in taxes on a shipment of Saga stuff from the US).
The cheapest (but slowest) is usually regular mail. The processing fee charged to the recipient is a flat rate of ~$10 per package (+duty & tax). They miss packages every so often as well, so stuff can occasionally arrive with no charges owing. And, with regular mail, you don't need to prepare a massive stack of paperwork (commercial invoice, NAFTA declaration, certificate of origin, etc.), so it's way easier. If you use FedEx/UPS you'll have to do all that paperwork.
If you go with UPS Standard, the recipient will be charged a brokerage fee based on the declared value of the shipment. It can be substantial; see the breakdown at this link (again, this is separate from duty and tax):
So, if you go with UPS Standard, there are advantages to having the declared value be as low as is reasonable. If you use any UPS service *except* standard, the brokerage fee is included in the price.
If the recipient doesn't have a UPS account they can also charge bond fees which are detailed at the above link.
FedEx generally works the same way. FedEx Ground's clearance charges are on page 48 here:
Regarding duty, if the item is of significant value, you may want to look up the HS code for the item and put it on the shipping paperwork (e.g. skis are 9506.11.10). There are often a number of categories under which someone could classify an item, so you might as well pick one that's duty-free instead of letting them pick one for you that's 35% duty. The tariff guide (duty rates) are here but it can be pretty cryptic to figure out: