Update 3/11: Updated with new information: Googlesync is limited to 5 calendars.

Last week Google came out and announced native sync support for Calendar & Contacts over-the-air (OTA) via a Push mechanism.  This was a long-awaited feature for many iPhone users (myself included), but there was already a competitor out in the field that many of these users were using : NuevaSync.

When it was first announced, I had been using NuevaSync to sync my Calendars & Contacts to Google for a few months, but I quickly switched just to see how it all worked.  I thought I’ld document my experience here.

Nuevasync

Nuevasync, available at http://www.nuevasync.com , gives you an Exchange server that you can add to your iPhone that will act as a middleman between your phone and Google.  It’s relatively easy to setup, and works well.  It supports an arbitrary number of calendars, be they writable or read-only, and supports most of the Google Contacts features.

Google Sync

While new, it’s already got almost all the features of Nuevasync.  It supports multiple calendars, although they report problems if you use over 5.  It supports Google Contacts, and bi-directional sync of all the data.  It functions almost identically to Nuevasync in that it also emulates a Microsoft Exchange server to enable the push features.

By default, it only syncs your “Primary” calendar, but you can visit http://m.google.com/sync once it’s working and configure which calendars you want to sync on a per-device basis.

Breakdown

So, what’s the major differences between them?

• Contacts with “other” numbers – With GoogleSync, phone numbers listed as “other” on a contact will not appear on your phone.  They stay in your google contact if you view it with the web interface through GMail, but won’t be sync’ed down.  With Nuevasync, however, they are.
• Speed – Google Sync is Faster, no doubt about it.  When you make a change on the phone, it’s not really noticeable since the phone immediately pushes the change to the Exchange Server.  Nuevasync then immediately pushes it to google, so the delay is just a few seconds.  With changes made on the web interface, however, you have to wait for NuevaSync to make a regularly scheduled poll before it’s available to your phone.  With it’s 7-minute polling schedule on the phone, that usually means 10-15 minutes before it’s visible, instead of less than 5 with the direct Google Sync.
• Support for “Other” services – Nuevasync has gotten alot of publicity for letting the iPhone sync OTA with Google, but that’s not their main objective.  Their goal is to create a service to allow your iPhone sync with many different services, Google was just their first service.  They already support Plaxo contacts, and are planning on adding support for other services soon.  They also have talked about allowing you to use NuevaSync as a kind of “Exchange Router”, if you’re one of the unfortunately people who have to deal with Many Exchange servers and are limited by the iPhone’s 1-push limit.
• Authentication & Security- With NuevaSync, you need to Authorize them (using OAuth) to read/write to your Calendar & Contacts.  With Google, of course they already have that ability.  It’s minor, but using NuevaSync does add another way for people to get into your data and another point of Breach if something bad happens.
• Number of Calendars: GoogleSync is limited to syncing only 5 calendars to the device, while NuevaSync seems to have no limit.

Sadly, neither service supports Push EMail (yet).  Nuevasync has long said they plan to implement an IMap-to-push-email gateway, allowing you to simulate Push email on any IMap-enabled account.  Google has had push-email since day-1 of the Android project, but hasn’t rolled it out to any other phones.  Hopefully this is the first step in rolling that out widespread.

So, I’ve made the switch.  I still have a NuevaSync account, but I’m not using it with my iPhone right now.  In fact, I’ve even revoked NuevaSync’s authentication credentials to my Google Accounts (Login to GMail, hit Settings, and at the bottom is “Account Settings”, it’s in there).

I’m going to keep a close eye on NuevaSync because they have alot of potential to create a real killer service if they succeed in integrating Yahoo calendars & contacts, Plaxo, maybe FaceBook, multiple push services, mail, etc.  But for now, I’m sticking with GoogleSync.