Yes, there certainly seems a lack of interest, at least on froums. On Australia's biggest forum all the other 375s are there, that is, H&H, 375 Wby, 375 Ruger and 378. Maybe only being in Rem 700 rifle is a reason but then there are a lot of Rem 700s in 375 H&H.
I think it would be a great 375. Using Varget it would duplicate top H&H loads with low pressure as does the 378. It kind of relates to the the 375 H&H about the same way as the 416 Rigb relates to the 416 Remington.
I really like the RUM case as it maximises out what can go in standard actions like the Rem 700 and M70. A mate of mine has done a lot with the RUMs and especially the 338 and has also taken the 338 to Africa.
But again, to get the full enjoyment the 375 RUM should give I think you will like playing with 375 H&H duplication loads. In a 378 85 grains of Varget is about 2650 with 270 grainers and extremely low pressure and the same load hits 2500 plus with 300 grainers and a bit over 2700 with the 225 grain Hornady. Loads for the RUM will obviously be a bit less powder
