Go for the citizenship mate...It would save you a lot of hassle (especially for GC holders who have to make it back to the US once a year in order to avoid losing it...In some cases I know peeps who've lost it even though they returned once a year and are still appealing their case for the GC to be reinstated).  Also, with dual citizenships given by the Nepali govt these days, it really is a good choice in applying for the citizenship.  These are my thoughts...yours could be different.  Go with what you think applies to your case.