Probably not but we still don't know the details of the MileagePlus (MP) for partners after March 1. If there is no revolution, I'd stick with MP but if the earnings on partners are severely "enhanced", consider switching.

Lufthansa Miles&More is attractive only for people flying business or first (or full fare Y). Flying discount economy, you'll have hard time getting Frequent Traveler (FTL) status which is a "gold-plated" *silver status with LH and absolutely no chance for Senator. With last year's gutting of M&M earnings, you get only 50% on such high classes as Q. With FTL, you'll get lounge access to only LH-group lounges, so only in a few airports (FRA, MUC, etc.) and some benefits on LH-flights but no alliance recognition except for *S which is basically nothing tangible. Redemption of M&M miles is also not that great with high fuel surcharges and only premium classes are worth paying YQ.

With UA Gold, you'll get full *G benefits but nothing more for non-UA flights. You'll get full lounge access, reasonable miles redemption (still very good mileage chart in economy because of no YQ, rather average for premium cabins) but few upgrade opportunities as the *A upgrade process is very restrictive (only high classes are eligible for miles upgrade).

With 50-70k yearly miles, you are likely safe for UA*G (but remember of 4 segment minimum on UA for status) but you may also have a look at traditional *A easy *G programs: TK, OZ, and A3 that may suit your travel patterns. The problem with the latter programs is that many discounted economy classes earn as little as 25% or nothing and those about 20k miles per year for *G may not be that easy to get. On the redemption side, there are some bargains in each of them but also fuel surcharges.