I'm 6'5" and saw 260lbs on the scale for the first time about 4 months ago.
I'm down about 15 lbs to date with a combination of cycling and a slightly better diet (nothing un-sustainable). I have had a bit of a pause with cycling in the last 2 weeks as we've moved houses, unfortunately.
I immediately had more energy after the first 1-2 months and started to get comments from people after the 2-3 month mark when the small amount of weight I've lost started to be more noticeable. I don't have any end target other than continuing to ride longer distances and feel better. I'd like to do some charity type events later in the summer, perhaps.
One thing that helped me immensely was tracking my progress each ride, whether it was indoor riding or using an exercise bike (in a hotel, while traveling). Also, I am lucky in that I am able to ride during my workday, which has really helped with the "no time to work out" excuse. A lot of folks I work with are into the sport as well, which is why I picked it over something else...