You never stated what you plan on using the rifle for. Are you planning on benchrest shooting, plinking, planning for some post apocalypic wasteland (hee hee). Get the gun that matches your needs.
If you are planning on putting a scope on the rifle then an AR has the advantage. There's more aftermarket accessaries for the AR and the buttstock is the right height if you're using a flat top. The AK's stock is a bit low and the scope mounts are a bit high. Your cheekweld isn't as good. It works ok but the AR is better if you're mounting some form of magnified optics.
Sturmgewehre has a good vid on YouTube about mounting a red dot on an AK. It seems like the mount soaks up a lot of heat though.
Your buddy may have a very good rifle but if he has to clean his AR constantly to make it run then something is wrong. I don't know about your friend's rifle but Olympic is not considered one of the better AR manufacturers by the AR community. I don't think I would base my opinion of all AR's on an Olympic rifle.
AR's are made in America by over a dozen manufacturers. Most are pretty good guns but there is a difference in the weapons even though they all look alike on the outside. For more info I would look at
www.tacticalyellowvisor.net , Sturmgewehre's channel on YouTube and
www.vuurwapenblog.com . There's a ton of good info out there.
One thing that I don't like about the AK is that most are assembled from parts brought into the US. They basically cut up a rifle and then someone here reassembles it. Quality seems to be all over the map although there are some very good companies such as Arsenal and Krebs. Of course you pay a lot more for these rifles. All of the cheaper AK's seem to come with a warning about looking for sloppy mag wells, canted front sights, keyholing (Tantals) and a host of other problems. Of course they all shoot but that seems to be a low requirement. I'd probably get an Arsenal if I was buying an AK. I would feel confident and well armed if I was using an AK and there's nothing wrong with the weapon. I just prefer the AR for my purposes at this time. To each his own. They are both fine weapons. I will say however that when I buy a firearm I expect it to be right and I don't expect crooked front sights, bad barrels or sloppily cut magazine wells. I would definately buy a higher end AK (and probably will sooner or later since I eventually get around to owning about everything).
Let's talk about AR reliability for a minute. There's over a million AR's out there in civilian hands and it's one of the most popular sporting rifles on the market. Someone is doing something right. Of course when someone gets a $1000 lemon then he wants the entire world to know. There's also a lot of people showing up at the range with lousy builds that don't work right. Everyone sees an AR and assumes the design is faulty instead of the individual rifle being a badly built frankengun. I've had experiences with a friends AR that fell into this catagory.
Then there's a lot of people like myself that are prior military. The rifles we used are abused in ways that civilian rifles will never be (even in peacetime activities). Let's put aside all of the crazyness like using a rifle as a step for someone to climb over a wall and just talk about the cleaning. Those of us that were in the military did a lot of stupid things to get our weapons "Clean." Bear in mind that the military's idea of clean usually doesn't match that of the civilian world. It's excessive and bad for the weapon. How often do we use carb cleaner, Spic & Span and all of ther other improper materials on our personal weapons? Those in the military often go overboard on their weapons because the level of cleanliness is unrealistic. This is not good for the rifle nor is the dissassembly that many do. I know that we used to strip our weapons down far beyond what is recommended and necessary.
Then there's magazines. Most reliablity issues with semi autos are mag related and I never saw a single mag taken out of service while I was in the Marines. If you got a jam you cleared it and called your rifle a POS. No one ever numbered their mags and no one ever disposed of a bad magazine.
Every machine that is non disposable has a maintenance schedule. Your car has recommended oil changes, your heat pump gets serviced, etc. On the other hand most military rifles are run until they fail. Once they fail repeatedly some parts may be replaced (or not). There is no 5,000 round service on a military rifle (the military is actually looking at some form of rnd counter for M4/M16's though just to address this issue. We're broke and it will probably never happen).
All of these things that I listed above contribute to ex military men and women getting out and spending the next 20 years trashing the AR / M16 / M4 platform. This is part of the reason why some believe that AR's are merely safe queens that only function when they are spotless and able to pass a white glove test.