When comparing Swift with Upper Hand - the main difference is in price and in credit-based services.
Upper Hand is definitely one of the more affordable tools in the market, so if price is the biggest factor in your decision making process - they may be a fit.
At Swift, we don't believe on competing on price because we want to deliver as much value as possible. We're firm believers of "you get what you pay for" so we're constantly aiming to deliver 10x the value of what our customers pay us.
If your business operates heavily on credits (either from memberships or packages), you should consider how you want these credits to work, and which tool makes the most sense from that perspective.
Both companies offer a clean, modern product with a strong online booking experience that'll save you time and energy.