Center Channel

ricred1,
The issue is not comparing one center speaker to another, it's as you say,
"the center should match the fronts."

With stereo only the image is created by 2 identical speakers. A different L&R would not create much of an image. Now with a center channel between the L&R, the image is created between the left to the center, then the center to the right. The perfect scenario is to use 3 identical speakers across the front, however that can only be done in specific situations. The next best thing is a timbre matched center to the L&R.

Take a look here especially the last line,

http://www.avtruths.com/speaker.html

Here's another good read about matching front and rear, but the principle applies to matching the center. Looking at that picture, think about the airplane actually starting in the left front speaker moving across the front, then through the room from the right front to the left rear. The only way to create that sound perfectly is to use all identical speakers throughout the room. Again, that can only be done in certain situations and timbre matched speakers will definitely be better than mismatched.

http://www.soundandvision.com/content/matching-front-and-surround-speakers

Your current center is a much better match than a different brand would be, but the timbre matched center should be better than that.

tls49,
Thanks. I read both articles including the last line, "With movies being recorded and mixed in the studio with 5 (6 or 7) identical speakers, shouldn't we be listening to our movies at home with 5 (6 or 7) identical speakers?"
In my situation it's unrealistic to have five Monitor Audio PL500 IIs. I'm thinking about the transition from left to center and center to right when viewing movies and I'm happy with my current setup. I've spent a lot of money(at least to me) on my 2-channel and just can't seem to justify spending almost 6k on the PLC350 II center to match my fronts. Thanks for your input.

@ricred1 - have you looked at the PLC 350 for sale on Audiogon?  For $2755 sold by tmraudio?  It's the first generation, but it may still be an upgrade from your Gold C350.  The woofer/mids are similar RDT drivers to the "II" series, but the tweeter is the old C-CAM (same as in your Gold C350).  The PLC 350 II has a different MPD ribbon tweeter as well as different crossover points. 

auxinput,
I've looked at the PLC350 that TMRAUDIO has listed. I will contact Monitor Audio and ask if the old PLC350 is a better match/significant step up from the Gold C350.
As a matter of fact I've reached out to TMRAUDIO to possibly trade my Dynaudio C20s that I use as rears, with the thought of having 5.1 surround sound with all Monitor Audio Platinum speakers(PL500 fronts, PL350 center, PL100 rears). I will keep my JL Audio F112 v2 sub.

auxinput,

after talking to Monitor Audio and considering the price difference between the series 1 and 2, I purchased the PLC350 from TMR Audio and should have it on Monday. I already have the Gold series one and everyone that I talked said, the PLC350 series one is a serious upgrade. I will post my thoughts on Monday.