I think your choice would depend on (1) water sources and (2) your own preference.
Water source -- if water sources where you mostly hike have fairly clear and OK tasting water -- then the UV will work wonderfully. If brown or green water, I would want some type of filtering.
Back a few years ago, I used Steripen for a short while, then switched to inline. Subjective, but I much prefer inline. All I have to do is scoop water, add some chlorine droplets, and I am good to go. Be it resting a bit or continuing my hike, I do wait about 20-30 min. for the chlorine to work -- before sipping water through my Frontier Pro inline filter.
If viruses are not a concern, then you can drink your water immediately after filling if you use the Sawyer inline filter.
Finally, while my Frontier Pro can also be used in gravity mode, I find myself not using that mode much, if at all. Firstly, I think gravity mode is good for filtering large volumes of water. But the only time I use "large" volume is when cooking -- except I don't use my filter since I will be boiling my water anyway. All other times, it's easy enough to sip water through the inline filter as needed. YMMV.