You can do whatever you want. I have not denied the good points about T-90, but you are hell bent on denying the advantages of Arjun. Now that is your problem. When presented with fact(s), you come back waving a magic wand, saying, "that is not an advantage." It would save you (and Damian), a lot of effort, if you simply at least made an effort to explain, instead of just stating facts and expecting people to take your words as blind truth. The way I see it is that, while you and Damian have a lot of information to offer, you guys really lack the capability to explain. Sorry, but that is what it is.
Dude. We don't know what to explain. You are saying T-90 and Arjun are of a different class. We are saying it is not. We even gave explanations for it. We told you the class difference no longer exists. The Arjun may be heavier, but it does not mean it is more capable. Other than that the T-90 and Arjun display the same exact capabilities when it comes to tank warfare with some slight advantages for T-90.
The advantages that you stated for Arjun aren't advantages at all. They are just small differences in design. Haven't you seen videos of tanks moving in desert terrains, there is literally no difference in how much dust is kicked up by any tank. It is a question of probability, like how much dust is present on the ground, if the ground is wet or not, wind conditions etc. BSRs and aircraft pick up tanks, in a tank battle dust plays no part in giving away position with modern detection techniques like radars, TIs and night vision. Ground pressure difference is fine if both tanks weighed the same. But they don't. The T-90 is lighter by 15 tons, pretty soon it will be lighter by 20 tons.
Arjun's main advantages are when you start thinking about how the west will use it. Give NATO a T-90 they will fvuk up their war. Give them the Arjun they won't. India does not follow Soviet doctrine, and neither do we follow NATO. We have our own and the T-90 fits in perfectly like a jig saw puzzle centered around a tank. The Pakistanis rejected the Abrams in tests because even they have their own doctrine where they believe Russian design tanks fit best. Abrams failed tests and that's another matter, but any army will buy a tank based on how they fight and never because the weapon itself is better.
As for specifications, Arjun has a greater depression. This is the angle at which the gun can move up or down. It is 20 deg for pitch up and down while it is 15 deg for T-90. Arjun has hydropneumatic suspensions which increases stability and hence accuracy of the gun. BMW type comfort too. A 4 man crew reduces workload. But it does not matter much for India because we have support infrastructure moving along with the corps. A large tank would mean more upgrades can be added(not a very big difference, really, but an advantage nonetheless).
However compared to T-90, Arjun needs a much larger logistics trail as it is a much bigger tank. This would mean extra trains for transport, extra men to train, extra maintenance and a massive new infrastructure to maintain the tank during both war and peace times. Comparatively the T-90 only uses the existing logistics trail for T-72. Major budget savings can be made. Training is more or less the same and thus there is little difference in converting a T-72 crew to the T-90. Not so with Arjun which has western training methods and tactics. So, advantage T-90 for training, logistics and maintenance.
The weapons available for Arjun aren't anywhere good. As already mentioned by Methos, Arjun's ammo is at best 80s level tech whereas the T-90s ammo currently available is ahead by a decade and newer ammo is coming out as we speak. The new ammos are upto the standards of modern NATO shells. Arjun will eventually be able to fire missiles after 2014(Lahat). Albeit Lahat is a superior missile, the T-90 had missile firing capability since the last 15 years. T-90 also has some capability against helicopters with onboard machine gun and some particular shells like HE-Frag. Arjun does not have any capability against helicopters due to the limitations of the Rifled gun. Arjun is not capable of carrying a mine plow like the T-90 can. It is being added on the Mk2 version. You can say that after 15 years, the Arjun will be able to do everything a T-90 could do since 2000. Some extra features are being added like an APS, but T-90 can have it too. So, T-90 has a massive advantage when it comes to weapons.
As for armour, the Arjun and T-90 have more or less the same armour. You can say the Russian supplied T-90s equipped with STEF will be better than the Indian made T-90 with Kanchan because STEF is a dynamic armour which acts like NERA while Kanchan is a ceramic. A dynamic armour is planned to be made for the FMBT. Arjun won't have one but will have add on NERA for Mk2 version. Other than that Arjun has design deficiencies which may not really be a big deal, but is at a disadvantage as compared to the T-90.
In the maneuverability department, there are no major differences. The only disadvantage that Arjun has is that it cannot snorkel like T-90 or pull a mine plow. T-90 is going to get a new engine soon, if not already present, unlike Arjun.
Hopefully this gives you an idea on both the tanks and you can come to your own conclusion.