@sicelo:
No, it doesn't oblige you to overwrite anything.
You can use Safestrap - modified TWRP recovery - in order to manage so called slots where Android OS ROMs and Sailfish OS can be installed.
You install the Safestrap from stock ROM but after installing it you can get rid of stock ROM.

There are several types of ROM slots available in Safestrap recovery.
Firstly, there is the stock ROM slot which uses partitions used by stock ROM by default.
Secondly, there are 4 slots which use loopback devices located on internal memory (in /sdcard/safestrap directory on any Android ROM).
Thirdly (or rather - sixtly), in modified by @Internauta37 Safestrap recovery available here there is the 6-th slot available. It uses "abandoned" webtop related partitions. Webtop was a Linux desktop environment available when using stock ROM in version 2.3. Later, at Android 4.0.4 upgrade, this feature has been removed by Motorola but the mentioned partitions are still available and it would be kind of waste of to not be able to use them. But be aware this slot is not supported by CyanogenMod/LineageOS by default and you have to modify ramdisk.img file in order to install ROM here.
In recovery modified by @timangus the 6-th slot is called altpart. This slot uses /webtop partition as /system and rest of partitions are the same as in stock ROM slot (it means it conflicts with stock ROM slot so you cannot install ROMs on both of them at the same time). It was created as /webtop partition is bigger than /system and installing for example LineageOS 14.1 leaves few space for installing gapps on stock /system partition. But be aware this slot is not supported by CyanogenMod/LineageOS by default and you have to modify ramdisk.img file or install mentioned on the website zip file in order to install ROM here.

So, in total there are 6 ROM slots available. You can have 6 ROMs installed at once (including SailfishOS) and use Safestrap recovery to switch between them.

Although, I am not sure how installing Maemo Leste affects Safestrap etc.

Hi there. Is it still worth it to buy a used Droid 4 nowadays? Thanks

In my opinion: No

I bought one because of the keyboard and announced Sailfish port. But the experience is bad (I still carry it with me because Android is often needed today, but also have a N9, N900 and N808)

Pros:
- is rootable
- has 1GB of RAM
- has hardware keyboard
- supports multiboot
- is small
- has Sailfish port
- may get working Leste port

Cons:
- Sailfish port is not in usable state. Charge is only readable in one of 10 boots. Can only be charged if Charge is readable. GPS does not work, Bluetooth does not work, Android support trick stops working, keyboard leds do not work...
- Battery life is bad if not in Sailfish port. Its somewhat ok under Android 4.4 Images, but most apps do not support it anymore. Android 7.1 eats the battery in two hours of use or 20 of standby.
- Keyboard has no control key, also keymaps have errors in multiple system images.
- For Android it is too slow for today's expectations of app developers.
- General phone specs do not excel in any way.

I imported two from US to have spare one, the spare works and only has a slightly broken USB port. Cables do not stay put but work as long as they are in the correct position. After my experiences I am sure I will not need it, so I will gladly send it to any active member here and only request shipping costs. (I live in Munich)

How much would it cost shipping to Portugal?

It costs about 5€. I may get lower rates by smuggling it among our company packages. I can tell you the precise price on Monday by PM.

I've got two Droids, one with Lineage OS 13 and one with 14
The 13 version gets me through the day, and the 14 version needs to be charged at least twice a day.
It was a lot better in the past, so I am not sure how much of the difference is the battery itself or the Lineage version.

If you only need a phone for whatsapp and occasional browsing, the Droid 4 with Lineage without gapps is absolutely fine.
My main and still preferred phone is a N900 - I use the Droids mainly for whatsapp (one for business, one for private conversations).

There is already a port that kinda works. I need one that can make and receive reliable calls (esp. my business phone) and capable of dual booting in Android for Whatsapp. So not suited for my needs yet (but hopefully the team will bring us there)

For me the worst "battery drainer" on Motorola Droid 4 (on LineageOS 14.1) is low 3G signal. Not medium but low, on the edge of signal drop.
Recently I was in place where signal coverage was really poor and I had to workaround battery drain by switching to 2G only. I still was able to browse most of websites using Opera Mini (although I switched its connection mode from HTTP/socket to HTTP as I found it working better on 2G).
Beside these "extreme" conditiions my screen on time is in between 4-5 hours and I charge battery every ~24h.

@Macros @t-b
Have you tried disabling zRAM and enabling SWAP on sdcard instead (not sure if it's enabled in SailfishOS) and enabling GPU rendering in programmer settings?
These "tweaks" significantly reduced lags on my device (of course keeping its low CPU power in mind).

@mp107

Thanks for your hints. I tried to implement them.
Switching to 2G only helps sometimes, but I already did that. Sometimes the battery is drained even in flight mode.

Disabling zram made the device nearly unusable and it crashed often. Also the constant swaping put additional strain on the battery.

Forcing GPU rendering was a good hint. Several Apps crash less often and run more quickly, also using less power.


I just got good news that one of my Droid 4s is now safe in the hands of deutch1976. I wish him fun exploring Sailfish and Leste with the device and of course I secretly hope he finishes the Sailfish port, so that I can use it as daily driver

Although your opinion I bought Droid4. Now it's waiting what OS is first ready to install.