Buy to let mortgage competition

I keep hearing of “coming” competition in buy to let market . Bosi ptsb…etc. but when I check rates they are all similar. Has anyone researched best interest rate in this sector for ltv<50% ? All advices appreciated.

Has anyone experience dealing with “haven” ?

Bank of Ireland is 4.99% and AIB is 5.35% and surprisingly Ulster has fixed 4.8% which means quite a variation out there.