I had a Rega Exact on my Rega P25 for quite a while. I bought it used on the A'gon and then sold it later on A'gon as I was satisfied with my replacement cart.
First, I liked the Exact. It was warm sounding and generally a nice match. However, I replaced it with a Denon DL 103R and found that the Rega sounded veiled compared to the Denon. Which I guess can be said when comparing any MM cart to a low output MC cart.
After I had lived with the Denon for a few weeks I went back to the Exact just to compare. I planned on using the Exact for a week or so before going back to the Denon. However, I couldn't make it past day two. I went back to the Denon and put the Exact on the market.
The Denon DL103R is a low output MC so you need a good phonostage with plenty of gain (55 to 60 as a min) or you'll need a transformer to boost the signle of the Denon. You can order the Denon from www.audiocubesII.com in Japan for $259 shipped. It's a great buy. And I didn't need any VTA adjustment for the Denon it's just about perfect at the stock Rega height.
I'm testing an Audio Technica OC9ML cartridge right now. It's been getting rave reviews just like the Denon and I wanted to see what the fuss was all about. I like it quite a lot, but I've only had it two days. It's higher output than the Denon (.28mV for the Denon and .4mV for the AT) but you still need plenty of gain. Again with the AT I didn't have to change my VTA. The cartridge is slightly tail high without any VTA changes or adjusters added to the P25. The AT OC9ML/II is about $350.
All in all, I'd have to say you can do better than the Exact for similar or less money.
Paul Green