Well, technical issues aside I do think o!m is not as bad as some people make it out to be, but it's far from perfect. It has some nice features. Having leaderboards is nice, and as a supporter you also get a country wide leaderboard and a friends only leaderboard. You also get what they call Osu!Direct, which is an ingame search and download system. You can spectate people as they play, and with supporter if you don't have the map someone's playing (assuming it's submitted to the system) it will automatically download it. Skins are relatively customizable, and will probably be a lot more customizable when Osu!Next happens. If nothing else, peppy is certainly dedicated to the game, and is constantly working on it.
Most of the things I have issues with are the actual system for getting your beatmap ranked in the first place, and the requirements to do so.
For example, you are required to have at least 2 difficulties, one of which has to be below 2 stars in difficulty, and are required to have a "proper difficulty spread" which essentially means anyone who wants to make a legitimately hard chart (like overjoy level difficulty) is forced to have somewhere around 6 (roughly) difficulties in their set. Considering how much more work it takes to make something at that difficulty level actually good, this is extremely discouraging. Additionally, you are required to add hitsounds to your map. The game has a few built in samples that you can use (and you can add custom ones as well), but applying hitsounds to each difficulty can be quite the headache.
Oh, and once you've done that you'll need to ask people to 'mod' or look at your map and make suggestions on how to improve it (which usually involves people requesting you change patterns that they find hard, even if those patterns have a good reason for being that way), because even though it's not technically a requirement for ranking, the people responsible for nominating maps for ranking usually require maps to have several mods before they will even look at it (because having a map disqualified has negative effects on whoever nominated it).
Oh, and in order to get mods, you usually have to either have friends who will mod your stuff, or post your map in mod queue threads on the forum. Of course, finding an open mod queue that will actually accept your map can be difficult, since many mod queues have restrictions such as "only 4k, only anime music, only maps less than 2 minutes" and such.
Not to mention that many kinds of patterns that you would find in o2jam/bms charts are considered flat out unrankable.
As a result of this, we have relatively few truly difficult beatmaps that are ranked, and a growing number of low effort low difficulty maps with no end in sight. Peppy has said that he's aware that there are problems with the system that he wants to deal with, but considering that he rarely ever consults with members of the community and instead tends to make decisions on his own and tell people to deal with it or fuck off and don't play his game, I have little faith that things will actually improve.