1xbet site is okay, but I think that nitrogensports is on a different levels.
Nitrogensports has a much more competitive odds, besides that, 1xbet are pretty much new to the gambling scene as the joined at the end of 2016, when nitrogensports are very old and were already managed to obtain high reputation, also, they have a very nice troll chat with cool games, so you can end up winning a free bet so you may won't need to risk anything for the bet at all.
From my own perspective, nitrgoensports are much more experienced with a much more competitive odds
When visiting 1xbet's page it says that they started their sportsbook since 2007 and 1xbet could be different from 1xbit.
For other options of betting I would recommend cloudbet and coinbet24 if you're in to betting team totals and btts because nitrogensports doesn't have those lines they're only limited to moneylines, point spreads and over/under totals. I've withdrawn more than 0.1btc from these sportsbook before and had no problems with them. These two also have live betting from my experience betting live cloudbet offers more live matches than coinbet24.