I've been interested in the senator chronograph for some time, but I am wondering if the chronograph movement is still modular? Searching thru the forum, it seems that there is also speculation on whether the 100 will (eventually) replace the 39 movement in GO chronographs. Any thoughts on whether the current Senator chronograph is still a good choice? Also was eyeing a Zenith El Primero T. Thanks in advance for any advice....