I recently rented a Roland TD30 kit to trigger Addictive drums to get the drum parts recorded for an album. When I was talking about this with someone they said that I didnt need to rent a TD30 to do this and that I could have got the same results with an older cheaper kit. He said an old TD9 would have worked fine because I only need the drum brain to have a USB out to connect to my computer and trigger Addictive Drums. He said it was overkill in a sense because I was not using the brain from the TD30 kit.
He basically said that when you rent these kits its mostly about the drum brains and for triggering I could have used an older cheaper kit.
Is this true? Can anyone verify this?

well yes, if all you are triggering ad2 or some other vsti like bfd or what have you, you wont be using the built in 'sounds' portion of the 'brain' so better, updated sounds portion of the newer brain will be of no concern. you will of course not benefit from any added or improved functionality of the newer unit, but all the basics that you require to achieve what you are wanting should still be there. the older unit should still have have everything you need like for adjusting sensitivity and the various settings. as long as you can connect it to talk with your pc you should be good to go.

+1 to what The Grim said.
If you only want to use VSTi Drums like AD2 it doesn't matter which E-Drum "Brain" you use, they all send the needed MIDI messages.
But, you said you rented a TD30 KIT, so you will probably benefit from bigger mesh head pads and a whole "playing is more fun / better" experience in general. 
And some software support "Positional Sensing" (not available with an older TD9 i.e.),
but I'm not sure about AD2.
 

Klaus
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And some software support "Positional Sensing" (not available with an older TD9 i.e.), but I'm not sure about AD2.

From the AD2 Key Map
 
CC37 Snare Rimshot (C#1)
CC38 Snare Open Hit
CC39 Snare Rimshot (dbl)
CC40 Snare Open Hit (dbl)
CC41 Snare Shallow Rimshot
CC42 Snare Sidestick
CC43 Snare Shallow Hit
CC44 Snare Rimclick (G#1)
CC75 Snare Sticks (D#4)
 
From that, I'm guessing that you'd need some sort of mapping between how that kit reports position, and what's available in AD2. Note that there are over twice as many Snare articulations when using the Brushes alternate mapping, available with the Modern Jazz Brushes ADPak:
 
http://www.xlnaudio.com/p...k/modern_jazz_brushes.

TheMaartian

Klaus
...
And some software support "Positional Sensing" (not available with an older TD9 i.e.), but I'm not sure about AD2.

 
From that, I'm guessing that you'd need some sort of mapping between how that kit reports position, and what's available in AD2.

AD2 has a MIDI learn feature in it (click the ? in the upper right of AD2 and choose "Map Window"). BUT... in the Map Window on the upper left is a "Map Preset" drop down... and both the TD-9 and TD-30 are in the "Roland" section.

What to keep in mind is that a basic Digital drum kit is mostly plain old velocity and on/off. Not much more than whacking a keyboard as far as the variation in sound that comes out. The pads are like hitting rubber coated disks. Your not going to get much more tonal changes than what velocity offers with a midi drum synth.  For a lot of drum parts this is just fine. You can always go in and edit and tweak things to taste, just like with using a keyboard or a Octapad type input device. 
 
But the Roland top of the line kits respond almost like a real drum kit. They are amazing beasts. So if your having a real drummer come in and do the parts they will be way more comfortable and play better, more naturally dynamic parts. 
It will sound much more like real drums especially if you do use the brain which has been optimized to pick up the little details.  I recommend recording the brain as well as the midi.  Also have the drummer monitoring with the brain. Their timing will be better. Even though it might only be a few ms, latency throws most good drummers off. 
You can sort out the midi mapping later. You might find there's nothing wrong with some of the Roland sounds too. 
I do believe there are separate audio outputs you can use.  
What you can do with just a hi hat set up on a good kit is a world of difference. 
 
 
  Put a real drummer on  basic digital kit and they will not be happy. 

I use my old M-Audio Trigger Finger to Trigger AD2.  The 16 velocity sensitive pad work great.  Mapping AD2 is simple and the mappings for my Trigger Finger and AD2 can be easily saved and recalled.
 
Not a bad Combination

AD2 does have a TD30 map in it, but it needs tweaking a little.  I can check my custom map if you like to find out what I needed to change (I didn't want to change the mapping within the TD30 itself).
 
I have found the MIDI latency to be somewhat high, e.g. compared to a MIDI keyboard using the same MIDI input; perhaps this is just because it's drums rather than triggering e.g. synth sounds, but personally I don't think this is the case; I have been meaning to try turning off 'Local Control' to see if this improves matters as I suspect that the TD30 does its own signal to sound trigger processing before converting to MIDI and sending that information (this is just a theory at present, but for sure the internal representation is not MIDI).
 
The biggest problem with the TD30's kit, indeed any (Roland) kit which uses the mesh heads, is the drum-centre hotspot issue.  I initially thought my kit was broken the problem was so bad.  It can be mitigated somewhat by playing with the head tension and trying to train oneself not to strike the centre of the drum head, but really this problem could (should) have been fixed either in the circuitry or even in the firmware itself but Roland simply did not bother.  Pretty poor engineering in my honest opinion, there is no way that they would not have been aware of this problem but they did nothing about it.