Good cart upgrade for an MMF-5.1?

I've had my MMF-5.1 with Goldring 1012 cart for about a year, and I'm itching to try another cartridge. I've been reading a lot of good things about the Denon DL-160, but for the price, I'm rather skeptical that it will outperform the Goldring 1012. My main goal is to test the Moving Coil waters without spending a lot. I'm also worried that I will have to give up some of the things that I love about the Goldring if I choose to move to a cheap MC cart: smooth, liquid-like midrange, excellent tonality, and deep bass extension. I'd like to gain a bit more detail, particularly in classical recordings. It seems like the Goldring has difficulty tracking on complex orchestral pressings.

So what can you guys recommend?

You may scoff, but prior to buying a new cart, try the Herbies mat. I was astounded at the synergy it had with my MMF-5. Deeper bass, richer sound... All the good stuff. I have to throw in that I much preferred the felt mat on my Linn to the Herbies mat, so it's not a panacea. Herbies offers a money back, so nothing risked, save a few $$ shipping. As a PS, I also found my MMF5 was far more vibration resistant by placing it on 3 small metal cones. Nothing special, just the cheap Dayton ones, as I recall.
I've had good results with a Denon 103R. I don't know how it will compare to your current cartridge. However they are quite reasonable used (lightly) and they certainly outperform their price point. They're easy to resell if you don't like it, and you could always have Soundsmith upgrade it for you for a bit more which will make it competetive with cartridges into the >$1000 range.