For 2019 it's between the DA 55-300 PLM and the DA 20-40. On our recent trip to London I did not take the 55-300, I did not figure it would be useful enough in the city, and I took a Turnstile 5 sling with the KP, 20-40, 15, and F50. That worked well, The 20-40 got 95 percent of the use and performed well. But, since I've had the 20-40 for less than three months, the 55-300 will be my lens of the year. The versatility of the lens is pretty amazing when you see how small it is when collapsed, then coupled with the KP is really performs. Many time I've used it over the DA*300 simply for the autofocus speed. When traveling via air it takes up very little space, I usually take the KP, 55-300, 15, 35 or 50, and either a shorter zoom or macro in the Turnstyle 10 sling. I couldn't take all of that if taking the DA*300, or even once of the previous 55-300s. The lens is excellent for nature and landscapes, which are two genres that I shoot most often.