Before the Apple (NASDAQ:AAPL) Nation starts chiming in on how silly I am to be cautious about Apple, let's make one thing clear: I think the company is probably one of -- if not the -- greatest of our generation. I'm also not saying investors should stay away from the company.

Recently, I've been reviewing  all of the companies in the World's Greatest Growth Portfolio.  Each year I rebalance the portfolio based upon a guiding principal: Invest first and foremost in companies that demonstrate exceptional levels of innovation, with special emphasis given to those that I believe will be around decades from now. Apple has been an important contributor to the portfolio this year.

Read below to see why I'm being cautious, and at the end I'll offer up access to a special premium report on Apple compiled by our resident Apple guru, Eric Bleeker.

Reasons to be happy
Though Apple may have missed earnings expectations during its most recent announcement, the company has still amassed an impressive record. Over the past four years, Apple has increased sales by a jaw-dropping 318%, while earnings per share have increased an even more impressive 550%.  

During that time, the company has basically grabbed a significant share of the smartphone market, and created an entirely new market -- that of the tablet -- almost from scratch. Along the way, rivals like Nokia (NYSE:NOK) and BlackBerry-maker Research In Motion (NASDAQ:BBRY) have simply been left in the dust.

As if that anecdotal evidence isn't enough, the company now offers up a 1.9% dividend yield, and trades for just 12 times trailing earnings and only 12 times free cash flow. All of these reasons combine to make Apple a very compelling buy at today's prices.

But there are concerns
There's little question about what helped catapult Apple from an almost-bankrupt company to the largest the financial world has ever seen: Steve Jobs. People have as many opinions on the man as there are grains of sand on a beach, but one thing is for certain: He was the main driver behind the company's awesome performance.

When Jobs passed away, I was concerned about what that could mean for the company's innovative DNA. At the same time, I was also aware that there were surely many irons in the fire that Jobs helped create that would be coming out for a number of years after his passing.

Since his passing, things have gone fairly well, all things considered. But I'm also aware that Google (NASDAQ:GOOGL) and Amazon.com (NASDAQ:AMZN)two companies that have their own visionary founders still calling the shots -- are also more than capable of filling in any gaps Apple allows.

The recent defection of a number of Apple executives leads me to believe that the actual make-up of Apple's innovative culture is undergoing some major changes. I guess that's to be expected, but it's still an unknown where once there was a pretty certain known.

As it stands, Apple makes up about 9% of the World's Greatest Growth Portfolio. I probably won't be eliminating the company, but I believe I'll be paring down its allocation.

As you might have noticed, I tend to focus a little less on numbers and a little more on intangibles when it comes to evaluating my investments. For some, that seems silly, but it's a strategy that has served me well, and fits with my style.

If you'd like a more numbers-centric, detailed view of where Apple stands in the technology field, I highly suggest checking out our special premium report on the company.

Fool contributor Brian Stoffel owns shares of Apple, Amazon.com, and Google. The Motley Fool owns shares of Apple, Amazon.com, and Google. Motley Fool newsletter services recommend Apple, Amazon.com, and Google. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.