I now have an 19inch iiyama CRT, and I think about buying an Acer H233HA 23 inch LCD/ TFT, 1920x1080, contrastr. 4000:1.
Does it offer the same or a better experience?

Don't gop less than 24" if you can.. and you will not regret it.

The day before yesterday my TFT 17" 4:3 gave up and this afternoon I purchased a 24" 16:9 Iiyama.
(Never heard of this brand anyway but I am not a kind of connaisseur you know, but according the salesman -for what it's worth- it ain't a bad choice at all.)
I have to sort things out of how to get the best FOV in IL2 but I will take a look at the Community Help forum for that.
With a nickname like that you must be Dutch so maybe you should take a look at MyCom 'cause I bought mine over there for € 199,- In my opinion it is quite a nice price...

Yes Dutchie here, I saw iiyama 24 inch at 4launch.
Not to pricy but the contrast 2000:1 and not 4000:1 with acer.
don,t know exact the difference.

Contrast ratios can be tricky, there is the true contrast ratio, and then there is the dynamic contrast ratio and the manufacturers don't like to tell you which one is which. You could have a monitor with a listed contrast ratio of 1000:1 and one with a listed ratio of 10,000:1 and the former still the better monitor.