Will a MC cart sound a lot better, by that I mean more detailed open stage?
From what I've read, by that definition of better, the answer would likely be yes. Here is an excerpt from an interesting short article that actually extols the virtues of moving magnet cartridges, but notes this major difference.
"Regardless of philosophy, these moving magnets are not so far behind in resolution as you might expect. Indeed, in resolving inner instrumental lines and the like, both would be hard to fault. The moving coils seem to have little advantage here, in this type of resolution, other than that attached to their rising top. The main difference, rather, has to do with spatial matters. Aside from tonal balance, it is in soundstage behavior that these cartridges differ most significantly from the moving coils. The expansive soundstage has firmly established itself as a desideratum of the High End. These cartridges can certainly produce width and depth, with the Audio Technica being somewhat more expansive than the Stanton. But on routine material, both, and particularly the Stanton, produce a narrower albeit precisely focused stereo presentation; narrower that is than many moving coils."
http://www.regonaudio.com/Stanton881AudioTechnicaATML70.html
For myself, the "expansive soundstage" is nowhere on my list of current priorities, and it is primarily the tonal character of cartridges that has driven my buying choices. I've always liked cartridges considered to be on the warm side of neutral (for example, Stanton and Grado as opposed to AT and Ortofon), and my preferred cartridge at present is the Shure M97xE. The excerpt above mentions tonal balance and the "rising top" of moving coil cartridges, and while not all are afflicted, it seems to be common. Below is a cut-and-paste from an earlier thread on the topic.
A commonly occurring "fault" of moving coil cartridges is a rising high end. Likely there are exceptions, but it's a fairly common generalization. As Positive Feedback wrote, "if you play many cartridges through many tone-arms, you'll find that some cartridges have personalities of their own which mounting them in various tone-arms does not change much. We say, 'Most moving coil cartridges have a rising high-end.' We arrive at this after listening and measuring many of them." Many reviewers have noted that this rising high end leads to timbral inaccuracies. Jonathan Valin of the Absolute Sound wrote, "With their rising treble response, moving coils tend to brighten up or thin out timbres in the upper mids and highs." In reviewing Grado's top of the line Statement (a moving iron design), Silvio Fernandez said, "Indeed in practically all cases, one way or another the moving coil alters the structure and timbre of the musical tone." Robert Greene once commented, "The inaccuracy of the rising-top moving coil sound is a matter of fact. Its musical significance is a personal 'value judgment.' But if live music remains our standard, as I surely hope it does, a judgment in favor of this rising-top sound seems misguided."
Nothing's perfect, so there are always compromises/choices to be made with respect to different sonic criteria. Some years ago, when I wanted to experience a wider, deeper, better-focused soundstage, I found I preferred a Grado wood-body cartridge with Grado's own phono stage over the moving coil options I heard. I also discovered that my power amp, a Linn LK280, was not going to allow the type of soundstage experience that I wanted; a switch to an Audio by Van Alstine power amp solved that issue (I had already been using an AVA preamp, which replaced a Linn LK1 that had developed a control board fault). Experiment widely, audition options if you are fortunate enough to have local dealers, and enjoy whatever best suits your own taste. It's all good!
