I have an Opto Core that is one of many mids I carry and I use it for straight backhand approach shots exclusively.  Thrown flat it will turn slightly and fade back a bit.   It can easily be manipulated to fade or turn more or less depending on the shot shape you want. I never throw it forehand since it turns and rolls even with a lot of hyzer. The Core is very similar to the Claymore with the Claymore winning this spot in my bag after a 100' throw-in.   I would consider it a good mid for a beginner. 

I had one of these about 5 or 6 years ago. I remember it being very straight overall with a very mild S shape. Little turn, little fade. Very comfortable rim for me, I enjoyed the feel. Plastic of course being great being Trilogy, I really like most blends they have. Especially the clear Opto or Lucid/VIP.

I would compare this to a Claymore or a better feeling straighter Buzzz. Easy 5 Star disc for me. I loved it. 

This is my go to mid range for easy distance and control. It is a great disc to learn shot shaping with because it will hold whatever line you put it in

Good disc, predictable flight, not as user friendly as the buzzz, or spyder but can make some tight short s-line shots that stop on a dime.

One of the best midranges on the market, if not THE best!  I have a 178g Opto Core and I can park any target up to 300 feet.  I use it for long gradual hyzers or anhyzers, tunnel shots up to 300 feet, and basically any midrange over 75 feet that's not downhill (that's where I prefer the Mako3)

Get this in your bag if it's not already!!!

I use several midranges, Warrant, Evidence,Truth and Core.  The Core is my favorite.  If I had one mid to play a game with it'd be the Core.  The disc flies stable and controllable for me.  It's the first disc I grab on approaches and any basket under 300'.

This was the disc that got me into disc golf. This is one of the most reliable, most forgiving, stable to understable midrange discs I have ever thrown. Great for learning the mechanics of driving, ideal for midrange gap shots.

I play in a lot of tight, heavily wooded, technical courses where this disc really shines. That being said, it will go understable quick into a wide open headwind. Even so, it is so predictable you can use that turn to your advantage.

 I can't recommend this disc enough.

The Core is great for straight shots, flex shots, and especially turnover shots. This was the first mid I owned that would stay turned over all the way to the ground and not fade at all.

The Opto Core is super glidey and gets easy distance, all from the most durable plastic money can buy. Gold Line doesn't seem to have quite as much glide, but it's a beautiful disc that excels at turnover shots even more so than the Opto. There are better molds out there for hyzer shots, but the Core can do just about anything with the proper release angle. Bag the Core with a Verdict and all your midrange shots would be covered.

I found the factory ratings to be accurate. But I could see where a beginner or lower powered player would find the Core to be more stable than the numbers, if they got one that's a little too heavy for their arm speed. All in all, the Core is great for any skill level.

My Core is in the Opto plastic, around 174-175g.

I've found the Core to be very easy to throw and has a ton of glide, having a beadless rim. It fits great inbetween the Pain and Fuse. The feel of the disc is similar to a Buzzz or Buzzz SS, and it's flight is probably close to a Buzzz or maybe a touch more understable, but more stable than the SS. Compared to a Lat 64 River (Fairway Driver), it's slightly less stable, and a little slower, as I use it for similar shots at shorter distances.

Where this disc really shines is for hyzer-flips, as well as tunnel shots, and stand-still shots. I throw it on a hyzer and it will stand up and go laser straight. Thrown flat, it will give you a long narrow S-turn, and a little anny it will hold that line until it flattens out and glides. This is the longest flying midrange in my bag (as a max 375' thrower, my Core can reach to about 280').

The cons, like with any glidey disc, is that an error is an error and it does not handle the wind well other than a tail wind. But for a wooded course, this disc is great, as your likely not to run into much wind, and the tight shots are it's strengths. You should put a Core in your bag, or at least rotate it in for the wooded courses. For a beginner, I think this would be a great straight or straight-to-overstable disc.

Stable mid in pretty plastic! I have the opto core and use it for upshots/approaches. Great disc for beginning players to learn with and can replace a buzzz in a pinch. Also, I should note that the opto plastic is the best quality "champ" or "Z" like plastic out there in my opinion.