just don't want a system where I have to use the computer to run trains

If that's the case, then definitely Digitrax is the way to go, if you want to use your phone/iPad as stated.  The LocoNet WiFi will let you do that.  Any system involving JMRI will require the computer if you want to use your phone/iPad. 

It's one of the reasons I've thought about adding a LocoNet WiFi to my system.  Sometimes I just want to run a train, and I want to use my WiThrottle app, but I have to fire up the computer to do it.  So I just use a basic throttle instead. 

The computer using JMRI does not run the train. you will still need to start and stop the train using a throttle or phone. JMRI makes programming a loco so much easier. Also having JMRI connected to the railroad allows you to see any potential issue you may have with the DCC system via the loconet monitor application included in the program. Take a look at the JMRI site. 

http://jmri.org/

Right on both counts Neil.  I definitely recommend JMRI for programming and troubleshooting, and use it myself.  Programming decoders with JMRI is FAR superior to doing it with any DCC system throttle.

But it does require a computer and an interface to the DCC system, like a LocoBuffer II.  Neither of these were in Pugatch's original requirements.  And even though JMRI won't run the trains by itself, if one uses it as the interface for WiThrottle on the iPad or iPhone, then the computer MUST be on and connected to use those devices.  

I'm not sure if Pugatch wants to get this involved in the computer/model railroad interfacing or not.  If so, then great.  But if, as he stated, he doesn't want to HAVE to have the computer on to run trains with his iPhone, then the Digitrax WiFi interface is a great way to go.  He can always add the computer and JMRI later if desired.

And . . . this is just my friendly opinion.  Your mileage may vary.  

One other possibility with the Digitrax Zephyr that no other systems have are the jump ports, that allow the use of dc power packs as throttles, which along with the LNWI makes for very cheap system throttle expansion. I have the Digitrax Zephyr system which is also what my club uses. I have been very satisfied with it.

I also have the LNWI which works great for using the smartphone throttle apps. I have one UT4D throttle and UR92 which were purchased long before the LNWI became available as I had no need of the fancy dual full function Digitrax throttles.

With the jump ports I was able to hook up two tethered handheld throttles that were purchased for less than 35 dollars each, which work great for yard switching which doesn't require walking around the entire layout. Quite often it is possible to find a used Zephyr for less than 100 dollars, and the LNWI unit can be found from Bob Bowditch for around 65 dollars with free shipping.

I recommend if you can try the systems first do so. NCE has a list of layout owners who have agreed to have people come over and try out the system. Especially try the throttles, you might use besides the phone app version, a local store may be able to help there.  There is nothing worse than having a throttle feel uncomfortable in your hand.

Also since you want to only run three locos you might look at the NCE Powercab system, disadvantage is you would need the computer for the wi-fi throttle interface.

Another option is the MRC system, has the wi-fi interface box like Digitrax does.

There is another thread here: http://model-railroad-hobbyist.com/node/32604, that you might want to read

I was googling for some images of different throttles and found this page, which shows Lenz, MRC, NCE, and Digitrax throttles. It has a little blurb on some of them.

http://www.dccguy.com/?p=5524,

Also there are some roll you own solutions such as DCC++, but that requires some electronics backgroud.

Awesome input guys!

Yes Mac to program ok but computer with USB stick to operate not an option we have one computer and my wife needs it for work

Dan Pugatch
Freelance HO Scale Layout Breakwater Branch: Connecting the Maine Coast to the World set in the 1980s

I just want to correct Neil that you certainly can run a train directly from JMRI.

You know, Honestly, for your requirements, MRC, NCE and Digitrax are all going to be fine.

 "Quite often it is possible to find a used Zephyr for less than 100 dollars, and the LNWI unit can be found from Bob Bowditch for around 65 dollars with free shipping."

     Bob Bowditch(bob the train guy) and Yankeee dabbler both on ebay should be able to offer you a Zephyr and LNWI unit at a good price. I've bought from both with excellent service. Also check out MB Klein website for comparision pricing, they are not always the lowest but always near the mark and are very reliable sources ....DaveB

I just want to correct Neil

Yes, and I can hammer a nail with a screw driver, but it is not the best tool for the job right..