Will I notice the differance?

You can't go wrong with Rega for musicality with detail and pure listenability and enjoyment. I've had a Planet, Planet 2000 and now a Jupiter 2000 and they're captivating to listen to for hours; extremely involving. I purchased all of my Regas used or as demos and have not been disappointed. I demoed the CD67SE before purchasing my first Planet and there is no comparison; the Rega is music, whereas the Marantz is pretty nice HiFi. I understand the new Apollo is quite remarkable.

The Cal Labs Icon Mk.II w/power boss is a very smooth, musical and overall good sounding player. It doesn't have the resolution of the newer players but it is very musical. You do realize it would be tough to get it serviced however.
The Sony Xa7es player is my favorite for musical players. It is uncanny how it is so rich and non digital but with as much resolution or more than any players mentioned so far.
It also weighs in at about 40 or so pounds and is built like a tank. Used, they are going for $800 or so and worth every penny. Much better player than the Rotel and others. It was a Stereophile class "A" cd player.
These observations are based on owning the Rega's, the newer Rotel that received all the good reviews, the CD67 and both Cals(the CL15 has higher resolution but also sounds more digital.)
The Sony would be an excellent match with your equipment.
Some of the newer stuff is just TOO good except with really good discs. The high resolution really shows the flaws. I had an Ayre CX7e and while an excellent player, I migrated back to the Sony.
I have a new Marantz SA11s1 on the way. I'll see how it does. It is reported to be very analogue like, similiar to the Sony. The Sony and the Marantz are/were $3500 players.
My system consists of a Theta DreadnaughtI 4-ch, Aesthetix Calypso, Vandersteen 5a's and misc. sources (the Sony lately but I have used the Wadia 861se and others recently.)

I second the Sony unit. I havce an older 707ES, and it easily beat several high-end budget players (rotel CAL), and matched a $5000 EAD unit.

My first recommendation is get rid of the RL-11. I had one of these, and grew to hate it. It really kills resolution, and makes the music sound muffled. They were trying to emulate a tube sound, but blew it in a big way. I ended up with a Classe CP35, which you can pick up here for around $300 - $500. This was one of the best purchass I've ever made.
Your speakers are very revealing, and deserve high resolution electronics. Also, if not placed well, can have bass problems. I tried a pair in my house. They sounded good, but the bass was never right. They sounded great in the store, though. This could cause harshness.

I own the Rega Apollo, and it is by far the most beautiful sounding cdp I've ever owned (I've also had the Planet 2000, the Ah! Njoe Tjoeb 4000 with upsampler, etc.)
The next batch of Apollos won't be here until beginning of March. So, save your pennies!
The Apollo does not make older cd's sound horrible; conversely, I found it makes them sound terrific. Whereas I could hardly listen to them before with the Planet 2000, with the Apollo they "come to life" and make it very pleasant to listen to them. The Apollo does not highlight the weaknesses of the older cds, but rather is able to extract more information from those discs and make them sound closer to a new recording.
The Apollo uses 20 meg of memory and 32 bit processing. One can easily hear the improvement in technology over standard 24 bit systems. Try, if at all possible, to audition one.
You can see my initial review of the unit on Audio Assylum:

http://www.audioasylum.com/cgi/m.pl?forum=digital&n=113988&review=1

You should be able to do well now in your selection. There are used Panets and Jupiters coming along since the people are upgrading to the Apollo. If you can stretch your budget, I would say don't hesitate to go for the top - the Apollo. But, even a used Planet 2000 would be a nice improvement. I had NO IDEA what I was missing in the music until I compared the them.