Am I missing something?

I have a system that I consider wonderful. It consists of Musical fidelity A3.2cr amp/pre, cambridge audio d300se cdp, Music Hall mmf 2.1 turntable, and Monitor Audio Silver 4i speakers on custom stands. I know it is mostly a budget based system, and I have never heard of anyone else saying anything possitive about these speakers, but I couldn't point out a single thing that they do wrong. I have heard Martin logans, sonus faber, vienna accoustics, paradigm, athena, and some others, and I know this sounds crazy, but I like my $850 Monitor Audio Silver 4i's better than them all. I have a very long listening room (almost 30ft by 13ft, speakers on the short wall) and they fill the room with a very pleasant sound. I know there are better speakers out there, but if I was unsatisfied with the other speakers I mentioned, what speakers do you think would fit my listening taste? I know stereophile auditioned my amp/pre with Sonus faber cremonas and said that the combo was "one of the best", and I didn't get a chance to listen to the cremonas, so these may be a good choice. Any other suggestions?
I agree with all the above. If you "must" tinker, play around with tweaks and isolation devices.
I don't think you are missing a thing. I have an old pair of Monitor Audio MA700 Gold speakers (6.5" two-ways with the gold tweeter). They are great. I have had them for about 12 years and never was really tempted to upgrade that part of my system. They are astoundingly good. Recently a woofer started to go bad on one. I am not sure what I will checking with MA the only option sounds like replacing both woofers at about $350 just for the drivers since the original speaker is no longer manufactured. This may drive me to change speakers, but without the "help" I would not consider changing them. I would probably have to spend at least $2-3k top make any real tangible improvement other than reinforcing the lower octaves. My opinion? Enjoy your good fortune in building a dynamic system that works.
It's an odd dynamic - We often sit in these forums and argue/agree on the merits and/or demerits of specific components but the truth of the matter is it has a lot more to do with the "system". I believe in "synergy". I once slammed B&W 804's because I thought they sounded shallow ... after taking my beating in this forum I went back and listened to different music on a different system and my opinion changed - in fact I couldnt believe I was listening to the same speakers. I will have a hard time saying anything bad about a specific component in regards to sound again.

Sounds like you have a great combination for whatever reason and I would keep it in tact: but I also like to play with tweeks. I like the idea of cleaning up the AC power. Isolation transformers can stablize voltage - filters can clean noise off the AC line and protect components.

Cables can make subtle differences as well - I found a used audio store in Portland OR (Echo HiFi) that will let me "try stuff out" at home before I buy. It's helped me make decisions and avoid a closet full of stuff that didnt work.
Happy with what you've already got? Why... that's un-American! I suppose the emperor's not got any clothes, either?

Maybe what you need is the all new Class A VonGallo 397-Moons Audio Hype Machine (Reference Version). It performs auto-Fremerization and makes any $25,000 "budget" system sound like a $40,000 budget system, according to all the reviewers.