Some generalities about bolt guns vs. AEGs
1. In practical terms there's no difference in range and accuracy if each is tuned up nicely. Out of the box they may both shoot like sh*t.
2. Clone bolt guns are pretty lousy...but at least the price has come down to reflect the quality level. There's a reason one L96 is $...and another is $$$. They look the same, specs might be comparable, etc....the devil is in the details, fit, finish, compatibility with upgrade parts. You can litterally buy a crooked rifle.
3. If your rifle is shooting ok...the fastest way to ruin it is to "upgrade" it.
4. There's no "upgrading" a part at a time...at least no single part that will have a significant impact on performance. The one single part that may do that is the spring...otherwise it's usually a combination of parts that makes for a result. Goes for both AEGs and bolt guns.
5. While there are quite a few parts that may fail in an AEG mechbox...due to its design there are definitely specific parts in a BA trigger mech that are subject to failure. And replacing those may cascade into replacement of many other parts. In airsoft it's not "if" it will break but rather "when", "how likely" and "what's it going to take with it"
6. Not so much now...but in general BA parts are more expensive relative to AEG parts. So "I'll just replace the tigger group" ends up costing as much as a mechbox overhaul.