I bought CM5 after I had bought the later two PS2 games in the series. I've not had time yet to play many games or get fully used to it, but so far I've not decided it was a waste of money. Both CM 2006 and CM 2007 have good aspects and bad, CM5 is no different
MENUS - it's a bit harder to move around the screens easily, menus are better organised in later versions but not vastly different. Search functions seem much the same, most of later options are there such as quick search (for player), clubs structured by region, country etc
TRANSFERS - you have to transfer list players to sell them, you can't offer them to clubs and hike up prices like later versions. There are bargains like Semjonovs of Skonto Riga and a certain Nemanja Vidic, and clubs in countries like Uruguay, Colombia, Serbia and Croatia offer bargain players as in later versions. You can approach to sign players out of contract or in youth teams, this can be a good way of buying without having to pay fees which is removed by CM 2007.
PLAYERS - same rating structure as later versions, one good thing is the skills are highlighted at a certain level ie if they exceed say 75 on 1-100 scale.
OPTIONS - took me a little while to find one or two things like the requests option to request upgrades of training facilities, youth squad and the stadium. The standard set-up seems there that is retained into later versions
TACTICS - not too different from later versions, simple to use or complicated if you want to be clever. The option to make quick substitutions, comment on the game or shout during the game aren't there yet.
GAMEPLAY - no option of quick result, 32x is the quickest speed and the in-game tactics are limited, but for a first attempt on the PS2 it is pretty good. I played only one competitive match, drew away to Forest so no obvious glaring ease so far. I've found later versions hard to win the Premiership with, have won the Champions League with Rapid Vienna on 2006 before and SPL with Falkirk, but never before found CM 'easy'. Time will tell if this is too easy, you can always make a game harder for yourself by not picking the better sides or trying to win titles with the existing squad etc ie set your own parameters with optimum difficulty.
So I'd say it is quite good so far, I'm not sure 1-5 is the best rating system as I might give this 7/10 or 9/10 eventually. If you've played CM 2006 (9/10) and CM 2007 (7/10) but not this then try it. And anyone who bought this and isn't too impressed, the later versions have their pros and cons, but are both very good - I've yet to play a game I've enjoyed more than CM, FM 2009 on the PC is over-rated, I need to try more recent LMA versions, but CM would make my top ten of all-time games. The main reason I don't play CM 2007 very much is because it is a fair bit slower than 2006 in gameplay and day to day e-mails - it asks too many questions. I sold off lots of players and set up a lot of scouting and other early activities, if you do too much then I find it freezes on 4th July. Can EIDOS please make a CM 2010 for PS2, I know the trend these days is to force people onto new systems/windows/consoles altogether, but this is a good game that can be made perfect