In a prior postings I talked about how we called the 727 "The Pig." The 727-100 was a bit better than the 727-200, but it depended on the type of engine your plane was equipped with. If you had a -7 P&W in the -100 plane, you were a pig. Some operators had higher output engines, but not many. I don't remember the charts, but if you keep the weight down to 135,000 or less the plane would fly just fine at 350 or even 370 depending on the OAT (outside air temp). Standard OAT or less should not be a problem for the -100. The -200 was a low altitude beast, unless you had bigger engines. When I taught Olympic Air,  their policy was never to go above FL350 in the -200. Remember what I said in a prior post... the 757 climbed better on one engine than the 727 with all 3 running!

As you climb, don't get slow. Climb at 280 to 300 KTS  then Mach .77 or better. The engines produce more power at higher speed.
Good cruise speed at altitude is Mach .78 to .84. As you go higher in the 727 the operating area gets smaller. This was called coffin corner. If you went too fast you were in Mach buffet, if you got slow you were in stall buffet.

I find the CS 727 to be a fun plane to fly. There are some bugs, but for the most part it does pretty well. I don't have the -200 version so I'm only able to talk about the -100. My 727 - 100 flies fine and all the instruments work. Only the trim is too fast using the trim buttons on my joy stick. The autopilot trim works fine.

I'm using the Logitech G940 HOTAS with rudder pedals. There seems to be no end to the button assignments in this system.

Have fun!  ;D