Dave,
I used a few Simmental/Fleckvieh bulls back in the '80s, and linebred my base herd of SimAngus cows to one particular line for nearly 20 years. Switched back to Angus bulls 6-7 years ago, but most of the Angus sires we've used just weren't giving us everything we wanted...so, I've gone back to Simmental for some of the cows - still using some Angus, some Shorthorn, and the cleanup bull is Angus, but I just like those Simmental-influenced cows.
The Dream On line seems to be good.
Dikeman's Sure bet has been a reliable calving ease sire here - and has a good balanced epd profile for virtually all the other traits that are important to me - including marbling, tenderness, API/TI.
We're also using three sons of Hooks Shear Force 38K to keep the calving ease, marbling & tenderness, without sacrificing growth, and all have good API/TI. Triple C Singletary on cows, Triple C Bettis and Hooks Pharaoh 16P on heifers. If red doesn't bother you, WS Beef Maker, another Shear Force son, would be at the top of my list, as well.
Would like to try Lucky Dice 187H at some point.