Canon has upgraded their venerable 70-200mm f/4L IS lens which I have been using since it was introduced.
https://www.bhphotovideo.com/explora...35423645394537
The Mark-I version of the 70-200mm f/4L IS has been my favorite lens which I have carried all over the world in tandem with an EFS 17-55mm f/2.8 IS lens on a pair of crop cameras. I can carry these two lenses and a pair of bodies at about the same weight as the 70-200mm f/2.8L (series) lens and the 17-55mm lens and a single body. The f/4L IS Mark-I is also my favorite portrait lens for people and the hundreds of rescue dogs I photograph each year.
I don't think that any major improvements are needed for the f/4L IS Mark-I lens. My philosophy is, "IF SOMETHING AIN'T BROKE, DON'T FIX IT" However, the MFD decrease from 4-feet to 3.3-feet would be nice.
I went the "el-cheapo" route when I purchased my first tripod ring for the Mark-I lens and bought a third party offering from Bay. It was an absolute piece of crap and I got rid of it and found a used OEM ring on eBay for a fraction of the new price. On the other hand, this lens is light enough to use with the camera mounted to the tripod. The tripod ring is nice but not a necessity. BTW: IMO, Canon has really dropped the ball with their tripod rings (for all their lenses) by not milling a pair of groves at the bottom which would allow the rings to mount directly to an Arca Compatible clamp. I have recently begun using a third party Kiwiphotos Arca Compatible quick release plate on my f/4L IS lens. https://www.ebay.com/itm/Kiwifotos-L...53.m2749.l2649 This plate seems to work fine. Anyway, I use my 70-200mm f/4L IS Mark-I lens hand-held most of the time...
I wish that Canon had produced a lens hood for the 70-200mm f/4L IS lens with a door to rotate a CPL (like the hood for my 100-400mm f/4.5-5.6L IS II). The original OEM hoods for the Mark-I lens are crappy and will not lock on securely. I lost one in Venice and another in China and have taken to securing the hood with gaffer's tape and or using a third party screw in hood (when I shoot with this lens on a crop camera).
I certainly won't trade in my f/4L IS Mark-I lens for the middling improvements of the Mark-II model but, I would recommend a person purchase the Mark-II as their first 70-200mm f/4L lens. Unless (and this is a big unless) they can get the 70-200mm f/4L IS Mark-I at a much better price than the Mark-II...