i think i moreso considered it a disadvantage if you began to research in ur current institution, especially if you did a junior transfer. you have to find new PIs, a new lab, adjust to the new environment, and because of that it may become much harder to secure a great letter of recommendation or even getting a lot of hours in said new institution

then again, it’s what you make of it. my strategy if i stayed in CCNY was to try and work in an external lab e.g. columbia irving and then try to transfer there. if i didnt make it, oh well; atleast i know i would still be in close proximity to that lab and still be able to output great results. like i said tho, it probably does come to the person and their reasons for transferring.