If its already set up but if you're a relative novice changing a cart and someone says 'just totally detach the tone arm, add this shim, attach it again and try not to snap the headshell off getting under there' then you'd be traumatised. And the cart won't last forever.
And the whole ethos of Rega now seems to be aimed at modding. So you buy your table, then a new sub platter, then new bearing, then a new belt, then you swap the platter... and one day you look at the tone arm and wonder where the rest of your table went. I was of the opinion my RP3 was amazing. Loved it for 6 years. Then I foolishly started listening to other tables. It's cool that British manufacturing is being recognized but, as I said, to pick all three is proper flag waving bollocks from What Hifi.