Yeah lag definitely is an issue for me, its worst when I try to beat water pulse vaporeon with my parasect and I just can't dodge any of them.
So I want to discuss the gym situation i'm in rn, I'm not sure how to go about it optimizing the situation for myself (my goal: get coins for as many days as possible while minimizing how much I have to go out to the gym and reclaim my spot. Some ethical questions arise due to the situation i'm in, to be frank though, my goal isn't to be as ethically pristine as possible, just to maximize what I gain from gyms).
A little background: In my immediate area, Valor is dominant (I am on Valor). There are two gym that are reachable with a reasonable amount of walking. One of them, has been and allways will be changing hands fairly frequently, but not so much that its unreasonable to cash in on it with one mon for two or more days.
The other gym, which is a church I live about a two-minute walk away from, used to be contantly valor for a week, switch to mystic for a short time, and then generally back to valor for the majority of the next week, so forth and so on. For at least a few months now, however, the gym has been a level 10 red tower, and the recent update has not changed that at all. It all started when someone placed a dragonite in the gym (coincidentally my mon, which was low cp and thus annoying to train on, was also knocked out the first time I checked on the gym and saw someone had put in a dragonite. I think this was the work of multiple ppl however, I have a very faint memory of going to the gym around this time and seeing some asian kids sitting in range of the gym at the church).
Ever since then, the gym has not been taken down, and because I am too low level / do not have super high CP mons like Dragonite or Snorlax (dratini spawns nowhere near the immediate area...), I generally am always the bottom slot. Because of this, I have been forced into the game of "knock out the bottom defender," but its highly inconvenient for me since I need my friend to come help me, since I don't use two accounts. As this game has continued, the gym has become progressively buffed with Dragonites. Now, the top 5 slots are all dragonites (All 2500+ CP, the top two being 3000+ CP and owned by level 30+ trainers). Earlier this week I got knocked out by someone who put in an egg in the bottom slot, and today I found that had been knocked out and replaced by another dragonite. There used to be a lot of 2100-2300 CP mons in the bottom ranks of the ladder, but they have long been knocked out, and now, I am the only one in the gym with my strongest 2030 Vap, immediately followed by a 2305 dragonite from a level 24 player. Only a few of the names I can recognize the names of from other gyms around the area, and they are the ones without DNites. I don't really know anyone else personally who plays in my area, but I can tell that most ppl who have placed mons in that gym before are discouraged to keep trying and play the "bottom defender game" (or simply cannot). The only reason I keep throwing my vaporeon in the gym is because I am so adamant about getting coins from the gym I live so close to, and I also have the help from my friend.
What do do now: I see two options ahead of me - Keep playing the bottom defender game (even with my recent insanely fast power levelling considering I live in the suburbs, I can't keep up with the other players who either have a dragonite, or are legit but a few levels higher than me already). The other option is to have my friend smash that stupid gym into the ground (He has a lapras that can do the job with the dragonites, his resources aren't super high but I feel pretty confident that with assistance from the pokestop next to the gym, it can happen), and then see what happens. I honestly don't know if it will return to the scene of constantly shifting hands (which won't be ideal for me actually, I WANT it to stay red, I just don't want to keep being the bottom defender who gets kicked out), or if ppl who I think are spoofers will quickly repopulate the gym. Legit though the benefit is just to get a better idea of who seems to actually be a spoofer and who is legit, because I am extremely sure based on past experience that valor will still dominate that gym even after the supposed spoofers get banned. It also may just be more interesting to actually play for that gym, rather than partake in this backstabbing business, but I do expect I'll have to be a little more active in maintaining control of this gym, and it may even destabilize to the situation of the other gym considering the current mechanics.
My current plan is to just keep doing what I've been doing, if I don't have to do the nasty business more than once a week, i'm good. It also gives me a chance to see if Niantic will change the gym system any further, and how it affects things in the area. Eventually though, if it just becomes absolutely ridiculous, I do plan to deal some heavy damage on that gym - whether I want ot get it torn down completely or not i'm not sure about though, and I'm interested to think what other people would do if they were in my position.