As mentioned the 5000 is a smaller saw than the 029. The Echo CS5000 is a very well made saw. Stock it feels a little underpowered perhaps, but has a lot of pulling power in the cut.
If you want a new saw you won't be happy unless you get one. If you want to unload the Echo shoot me a PM.
If you want to get more power out of the Echo that is easy to do.
Clean or replace the air filter. This makes a big difference on this saw.
Muffler mod. From simple added hole to extreme gut and new deflector. Unless you port it the simple added hole is plenty.
Adjust squish. The Echo CS-5000's I've worked on all had lot of room to increase compression this way in just a few minutes.
Port job. A little port work will really wake this saw up. Proper porting moves the power band into much higher RPM's on this saw. Torque will be even better.
I've worked over a few CS-5000's and CS-4600's. They are some of my favorite saws. Bullet proof construction all the way around, they run forever and take a lot of abuse. Very powerful with basic mod work. You can easily set that 5000 up to outcut an 029
Mr. HE