Indus GT upgrades

I am planning to order some parts from Best and saw that they sell a ROM Upgrade for the Indus GT. Does anyone have experience with that and how does it compare/relate to the RAM upgrade? Is the RAM upgrade required to speed up the drive or is it required only when you want to run CP/M (which is an urge I seem to be immune to as I had the heart to sell a perfect working Amstrad 8256 for a sum so paltry that my aging memory refuses to recall it - and which BTW must be the climax of CP/M Disc format incompatibility with its 3" "floppies", a format that sadly failed to take the world by storm).

Thanks to all Indus users and sorry for thread drift in OP