These two vapes are completely different and serve different purposes, so I suggest you determine what you want first. Here's something I wrote a while ago and will post it here for you. Read this, read some of the model specific threads, and good luck!
Things to consider when purchasing your first vaporizer, in what I consider to be order of importance:
PRICE! How much does price drive your choice? You can get a very good vaporizer for as little as $150, or you can spend upwards of $700 if price is of no concern. Just remember, more expensive does not equal better in the vaporizer world.
Delivery system. In what social settings will you vaporize the most? If youre a big party user, then consider a bag delivery system (Extreme, Volcano, Herbalaire, Mystfire, etc.). All of these units also have an option to use the whip, except the Volcano.
Efficiency. Do you have tons of herb and just want the biggest hits attainable, or are you more concerned about making your herb last, or are you somewhere in between?
Manufacturer. Make sure to buy something from a reputable manufacturer (the straightest answers on the web to this question are right here on fuckcombustion.com). Dont buy something cheap that you dont know where it came from. Chances are it may have come from China, where it has been confirmed that some models are made with lead paint in the vapor path.
Stealth. How discreet do you need to be? Some vaporizers are easy to put away in a closet. Others stay out in the open and look like a potpourri warmer, etc. Some scream of paraphernalia.
Learning curve. Do you want something easy to use (usually means less temperature and delivery options, but not always), or are you comfortable with a steeper learning curve?
Temperature control. Do you want a digital control with the temp readout, an analog control with just a dial, or no control using a unit that is preset at the factory? Any vaporizer worth its salt will produce vapor regardless of the temperature control feature, but more control can be good if you will be vaporizing different types of herbs.
I suggest you sit down and answer these questions yourself before buying anything. Start with price, because if its out of your price range, none of the other variables matter.
Once you have answered the above questions, its time to start reading about different vaporizers on this forum. Dont jump to a thread and post your questions without first reading the thread or, at least, using the search function to find answers. Most of your questions have already been answered in these threads. If you cant find the answer to your question, go the Ask the Vaporists forum and post it up there. Most of the members here want to help you, but dont want to clutter up model specific threads with repeated questions.
Here are my opinions on a couple of units to give you an idea of how to think about a vaporizer when purchasing it:
Purple Days
Pros: Great company, great price, unbeatable efficiency, very stealthy.
Cons: Not the best party vaporizer, but it can be done.
Neutral: It has no temperature control, which I personally think is a good thing. The lack of a temperature control makes the learning curve easier, but makes it less adaptable for other herbs.
Extreme
Pros: Has a whip and bag delivery system, great customer service, very versatile with tons of bells and whistles like a remote, moderately efficient.
Cons: Is not the best on the market for either whip or bag delivery, but is the best at doing both.
Neutral: It is a new design that is going through some growing pains in terms of manufacturing defects, but the companys unsurpassed customer service more than makes up for it.
VaporGenie
Pros: Good company that will send free replacement screens and mouthpieces, truly portable and does not need electricity, great price, moderately efficient.
Cons: Can use up a lot of butane, can burn your herb, semi-steep learning curve.
Silver Surfer
Pros: Cool design, good price, might be the thickest hits available on the market, customizable.
Cons: Low stealth
This is not meant to be an exhaustive list of good vaporizers or their features. I own all of these vaporizers, so the points made here on the other three units are from experience. This list was done to give you an idea of how to best think as a newbie to vaporizing. Good luck, and remember to post a review of whatever you buy, especially if we dont already have one on the site for the model you chose!