My best advice is to get fit.  You need to be careful with the TM drivers, because they are a whole inch longer than the the standard length of drivers.  Between the the three drivers I would stay away from Razrx.  (Just my personal opinion)  I have tried out and played Cally clubs, and they don't compare at all to Titleist and TM.  The 913 and the Razr both feature personal adjust-ability and offer the most forgiveness.  My cousin currently plays the RBZ and loves it.  He has gained almost 20 yards compared to his old driver, and is hitting more airways.  When it comes down to it, its just whatever you feel more comfortable using.  I can't express to you how much custom fitting will benefit you on deciding which driver is best for you.  

Traditionally TM spends all their time and money in the club head, then uses a cheap shaft. I previously had a TM '09 Burner because it had a better shaft than years past. I just purchased the 913 D2 with the Diamana S+ 62 Stiff Blue Shaft (on ebay for $285!). In my opinion Titleist has far better shafts than TM. One major difference with the 913 compared to the Rocketballz is the 913 has a forged face. Which i believe is a first of its kind. The new face is faster and creates more distance on off center hits. That is also the feedback given from the PGA professionals that used in last year; including Rory Mcilroy who used the 913 when he won the PGA Championship 

Hope this helps!

Colton - agree with the other 2 answers.  Even across one OEM line there is no guarentee that all stiff shafts will play the same.  Even torque and kick point are not standardized let alone stiffness.  Never buy based on ads alone.  $300-400 is a lot to spend to find out it doesn't fit you as well as your old one.

Jeremy - I do a fair amount of e-Bay shopping (going to a big box store doesn't do me any good when they have no LH clubs).  I have to ask how do you know the 913 is authentic?  I have only seen odd custom sizes (12 degree with a stiff shaft, 46.5 inch shaft as an example) available and even the used 910Ds are still at $200+.. $285 is amazing if it is the real deal.  And... did you know the club was the right by having someone spend time with you at a brick and mortar so you then went online with the specs they gave you?  I only fill in clubs after buying the first after getting fitted.

I base authenticity off the sellers history and reviews. I only buy from users who have extensive history combined with great reviews; making sure there is a fair amount of recent reviews from buyers who have bough the same or similar equipment. I've never had an issue with authenticity when it comes to golf equipment. Now you may have a tougher time since your looking for left handed clubs as there are not as many for sale. But I do double check the specs found on E-Bay with the specs from Titleist.com.

Before I buy any golf equipment on E-Bay, I do always go to the local Golf Galaxy or Dicks Sporting Goods and demo multiple different drivers/ irons. When deciding on a Driver this year I probably went to Golf Galaxy to demo drivers 3-4 different times lol. After narrowing down to the Titleist Driver, I spent some time hitting the 910 & 913 model to see which one I liked better and what Shafts fit me best. I Thank the employee who helped me out, go home and buy it on ebay for far below what they can sell it to me for! :). None of the employees really care because they don't get paid commission anyways. When I get this club in the mail I'll go the range with my golf coach and make sure the "SureFit" Tour Hossel is set properly for my swing. I'm sure you can even take it to a Titleist Rep to get it fitted after buying it online. As long as its a Titleist Driver they won't care where you buy it from. 

Colton - BTW when your asking an employee at the local golf store what are the differences between drivers make sure you don't base your full opinion off what one employee says. In my experience it's best to ask more than one person and combine that with some online research; As some of those employees don't know as much as you think they should know about their equipment. Obviously it wouldn't be a bad idea to include what your high school coach has to say about the different clubs.