DTCI

I am new to the forum and have been reading trip reports with interest.
We have booked our virgin flights for next summer flying DUB-LHR-SFO. LAS-MAN-DUB in Upper Class.
We are starting from Newcastle and flying to Dublin the night before. As we have a through ticket from Dub to SFO via LHR our luggage will be checked through from Dublin.
When transferring terminals at LHR, would you use internal terminal transfer bus or exit the terminal and get a taxi to DTCI to get full experience of UC?!!
Many thanks
We have booked our virgin flights for next summer flying DUB-LHR-SFO. LAS-MAN-DUB in Upper Class.
We are starting from Newcastle and flying to Dublin the night before. As we have a through ticket from Dub to SFO via LHR our luggage will be checked through from Dublin.
When transferring terminals at LHR, would you use internal terminal transfer bus or exit the terminal and get a taxi to DTCI to get full experience of UC?!!
Many thanks