What to expect from flatcap

Hi folks,

My (former-Naim)dealer said he could probably
get me a new flatcap for my CD-3.5 for a fair
price (he stopped dealing Niam just a week after
I purchased my CD-3.5) Now they're doin' Linn instead. O,well. making mistakes is human,eh?

Now, I'm looking for an affordable and locical way to upgrade my humble system (Nait-2/3.5/MA studio-2SE's)
To the people who added a flatcap to their 3.5:
"What kind of improvements can I expect ?"
will it be a big improvement ?

see ya' guys.

Greetings,
Alco.