I'm in the middle of the road on this one.
You have to treat this deck IMO like ReapLace (see my affinity for wierd combo decks helps me here). When playing against ReapLace some people let the Laces trhough since they don't do anyhting, and try to counter the reaps. I will usually hard-counter a Lace, but if I have to FoW it I let it go (seeing as it isn't a direct threat and not worth two cards).
I found the deck much easier to beat if you did it the other way around--counter the Laces and then every reap he draws is a dead-ass card. If one lace get's through he suddenly has 4 instant speed regrowths in his deck.
Personally I would consider Land Tax important enough to hard-cast counterspell, but I wouldn't pitch something to a Force to counter it because, yes it's true, it doesn't acrtually harm your game in any way directly.
Scroll Rack is usually absolute garbage by itself in this deck, but Tax is quite good as it thins his deck allowing him to draw more threats. It's almost the same as him drawing cards period.
In games two and three you have extra enchantment kill in the board (Aura Fracture) to kill Land Tax--even multiples.
I think trying to landscrew a mono-white deck is going to be exceedlingly difficult to do since all your Wastes are dead.
Also if you have Gorilla Shaman you don't need to counter Scroll Racks.
--Matt
By Big Blue on Sunday, October 14, 2001 - 07:23 am: Good points, Matt - there are "must counter cards" (like Mindtwist,YagWill,...), "must not counter cards" (like an early Lightning Bolt, ZOrb) and many cards in between. In fact, no card is strictly "must" or "must not", though there are tendencies.
The Land Tax situation is accurately described by Matt, IMO: If you can Mana Leak/Drain it, do it (most of the time). If you have to FoW it, don't do it (most of the time).
But, as always, such rules of thumb are like crutches: An aid for disabled, but an obstacle for everbody else. Sometimes, the JP route of Mindtwist/Balance is better, sometimes... Well, there are zillions of possibilities, after all, that is why we love Keeper 
Just close your eyes and Use The Force when you have to figure out whether you should counter Land Tax or not
Concerning the mana-screw issue: Sure, most of the lands are basic ones - but Parfait usually has only 24 mana sources, 10 of which are not basic lands. It is not that you completely screw them, but you deny them (at least) 3 lands, which is not so bad, I'd say (apart from the card disadvantage/improvement of draws issue). You slow them down, which gives you time to go nuts with EOTFOF, Tutors, YagWill, whatever. I am not saying it is always advisable to follow this route, but as a tendency, I'd prefer to counter Land Tax with a non-FoW counter.
Finally, from my own tourney experience with Parfait on the Parfait side, I must confess that I always felt uneasy w/o Land Tax in my inital hand. I lost most of the games against control where I had no Land Tax and won most of the games where I had it.
By Rakso, Patriarch & Rules Ayatollah (Rakso) on Sunday, October 14, 2001 - 08:18 am: Maybe it depends on how you can read his hand. I'm skewed towards letting Land Tax go, I think, because I've played against more Enchantress than Parfait lately, and an Enchantress is WORSE than an Argivian Find.
Maybe I'd agree with Matt on the hard counter IF it's not your last one and IF you will be drawing more very soon (FoF range).
By Big Blue on Tuesday, October 16, 2001 - 05:29 am: play Duress, then it's easy
By Rakso, Patriarch & Rules Ayatollah (Rakso) on Tuesday, October 16, 2001 - 07:34 am: Huh?
By Matt D'Avanzo, the Sylvan Librarian (Matt) on Tuesday, October 16, 2001 - 09:29 am: I think he means you get to see his hand and judge whether or not countering it is the correct play. I think...hell I'm not sure.
I don't know, I've seen a few different people (like 4) come to Neutral Ground NYC with Parfait and they've all gotten their asses handed to them by Keeper, mono-U, and even Sligh (which I totally didn't get, but oh well). I really don't understand how it got this repution as a control-killing deck.
>>>In fact, no card is strictly "must" or "must not", though there are tendencies.
This is true. I won the last type I tourney at Neutral Ground because I decided to NOT counter a turn two ancestral.
--Matt
However I am 7-0 in multi-player ith Parfait. Everyone has decided that they HATE the deck and the grey hound meets a seal arfing noise (I decided that's what a Pegasus would sound like) I make when I make or attack with Mesa tokens.
By Big Blue on Tuesday, October 16, 2001 - 02:58 pm: @Rakso: Matt's interpretation was correct
@Matt: I think, mainly because control did not know what to do with Parfait initially - so they tried to counter Land Tax+Scroll Rack+found Land Taxes+Sacred Mesa and suddenly an Abeyance went through followed by Replenish or a Sacred Mesa or (against Masticore-less BBS) a Story Circle. It was a new, ingenious deck. And it was played by its creator in ToC and he was second, to everyone's surprise (Parfait is NOT easy to play, especially against control - my scores in games where like 1-0 or 1-1 when I tried Parfait once in a tourney - never had time to finish the 3rd one - but this is not Parfait, it was just the combination Big Blue&Parfait;)