The 920 is not a new phone (it came out in 2012) but still is one of the top windows phones, being topped only by the 930/icon and 1520. Yes,the higher the number, the better the phone with a few exceptions...The 830 is considerably better than the 920 in some ways (ts pretty much the successor),the 1320 is a budget phone, and the 928,925,and 920 are all equal with minor tradeoffs to eachother so here is how the whole system is set up
500's =budget phones
600's=slightly better budget phones
700's=mid range phones
800's=better midrange phones
900's=flagship phones
1000's=flagship camera centric phone's
1300's=budget phablet
1500's=flagship phablet
So for the most part, the higher the number the better the phone, and the higher the number the phone is in it's class,the newer it is (ex: the 930 is newer than the 925 or the 920)
As of right now the top windows phones are basically the 930/icon and the 1520,but the 1520 is only on att and the icon/930 is only on Verizon in the U.S
But long story short, the 920 is a decent phone and has pretty much all the Lumia features and benefits but if you want the best you may wanna opt for the 830, 930/icon or 1520