Which is more important?

I agree with Onhwy61 - you need to assess your systems shortcomings and develope a plan. Were I you I would get the best neutral monitors & amp that I could afford, and a good sub woofer. (If you are happy with your speakers and amp as they are then perhaps you should do nothing! Its all about synergy). This would allow you to move from quarters to quarters without having to worry much about room size etc. Once chosen I would let those components dictate future changes, that is your pre-amp and CDP. Your turntable set up is just fine as it is.

Nice system, you could play around with some tubes for something a little different..But, the next level for you is small steps as your system has gone past mid-fi level IMO.

I would also note that with your present quarters you have the same problems many apartment dwellers face and a total and lasting fine tune of the system is not $$$ something you may like to do in someone else's space.

Do you have good speaker stands? Onhwy61 has some pretty good advice for you IMO.

Dave

Resonance control and speaker placement. This can be done very inexpensively per many of the threads here. Try cardas.com for placement recommendations and try any number of resonance tweaks, including even the very cheap. Oh, and lifting your cables off the ground is huge along with proper polarity (see the Wood Effect book)and isolation.

I know most, if not all my problems come from my listening/dining/living room. The sound is a bit bright and thin. The sound stage is not bad considering the area, although a bit narrow. Plenty of detail. I think what I am looking for is a sound that is a little more rich, full and engaging. I am not great at describing what I hear, but I know what these components have the ability to sound like together and separately. And I know it could be better. I am also surprised that as great as the Nottingham sounds it does not "blow away" the Pioneer, as it should. I know this table deserves a better cartridge. Is it possibly the Rega reviews are some what exaggerated?

The room and speakers together are the most important component. The two interact and should be viewed as a system. Room gain can supplement the bass of a smaller speaker or make a big one too bloated. How the room reverberates can determine how bright/natural a speaker sounds.

You can't have speakers that are too good. The used market, internet direct sales, and DIY construction of projects by _good_ designers can all keep the price tag reasonable there. However, a sub + monitor setup will give you more placement options to work arround poor rooms.

After that, things to minimize your rooms' effects would be good. A Tact room correction system, parametric EQ for the bass, tapestry you can hang on the wall to kill high frequency reflections, etc.