If the length of the loan is the same (making the payment roughly the same) and you can cut your rate at all it's still worth it. I mean any rate reduction is less money you're giving away on interest right? I'm willing to refinance my student loans if I can save at least $250 over the length of the loan.
A 0.43% rate cut will save you $180 the first year plus whatever referral/signup bonus you get (typically $100-$200). Is a $300 return in the first year worth the 1-2 hours of work and hard pull? I would say most definitely. You can always refinance again to lower rates as your salary and assets grow.
Other companies to look at:
Earnest, Sofi, Citizens Bank, Credible (search engine)